The skb_gro_header_slow function in include/linux/netdevice.h in the Linux kernel before 2.6.39.4, when Generic Receive Offload (GRO) is enabled, resets certain fields in incorrect situations, which allows remote attackers to cause a denial of service (system crash) via crafted network traffic.

An updated rhev-hypervisor package that fixes several security issues is now available.

The Red Hat Security Response Team has rated this update as having moderate security impact. Common Vulnerability Scoring System (CVSS) base scores, which give detailed severity ratings, are available for each vulnerability from the CVE links in the References section.

The rhev-hypervisor package provides a Red Hat Enterprise Virtualization Hypervisor ISO disk image. The Red Hat Enterprise Virtualization Hypervisor is a dedicated Kernel-based Virtual Machine (KVM) hypervisor. It includes everything necessary to run and manage virtual machines: A subset of the Red Hat Enterprise Linux operating environment and the Red Hat Enterprise Virtualization Agent.

Note: Red Hat Enterprise Virtualization Hypervisor is only available for the Intel 64 and AMD64 architectures with virtualization extensions.

The RHBA-2011:1254 update introduced a regression in the Linux kernel's Ethernet bridge implementation. If a system had an interface in a bridge, and an attacker on the local network could send packets to that interface, they could cause a denial of service on that system. (CVE-2011-2942)

A flaw in the Linux kernel could lead to GRO (Generic Receive Offload) fields being left in an inconsistent state. An attacker on the local network could use this flaw to trigger a denial of service. GRO is enabled by default in all network drivers that support it.
(CVE-2011-2723)

The way IPv4 and IPv6 protocol sequence numbers and fragment IDs were generated could allow a man-in-the-middle attacker to inject packets and possibly hijack connections. Protocol sequence numbers and fragment IDs are now more random. (CVE-2011-3188)

Non-member VLAN (virtual LAN) packet handling for interfaces in promiscuous mode and also using the be2net driver could allow an attacker on the local network to cause a denial of service.
(CVE-2011-3347)

Red Hat would like to thank Brent Meshier for reporting CVE-2011-2723;
Dan Kaminsky for reporting CVE-2011-3188; and Somnath Kotur for reporting CVE-2011-3347.

This updated package provides updated components that include fixes for numerous security issues. These issues have no security impact on Red Hat Enterprise Virtualization Hypervisor itself, however.

The security fixes included in this update address the following CVE numbers :

CVE-2011-2695, CVE-2011-2699, CVE-2011-3191, CVE-2011-1833, CVE-2011-2496, CVE-2011-3209, CVE-2011-2484, CVE-2011-3131, CVE-2009-4067, CVE-2011-1160, and CVE-2011-1585 (kernel issues)

CVE-2011-3378 (rpm issues)

Users of Red Hat Enterprise Virtualization Hypervisor should upgrade to this updated package, which resolves these issues.

Updated kernel-rt packages that fix several security issues and two bugs are now available for Red Hat Enterprise MRG 2.0.

The Red Hat Security Response Team has rated this update as having important security impact. Common Vulnerability Scoring System (CVSS) base scores, which give detailed severity ratings, are available for each vulnerability from the CVE links in the References section.

The kernel-rt packages contain the Linux kernel, the core of any Linux operating system.

This update fixes the following security issues :

* A malicious CIFS (Common Internet File System) server could send a specially crafted response to a directory read request that would result in a denial of service or privilege escalation on a system that has a CIFS share mounted. (CVE-2011-3191, Important)

* The way fragmented IPv6 UDP datagrams over the bridge with UDP Fragmentation Offload (UFO) functionality on were handled could allow a remote attacker to cause a denial of service. (CVE-2011-4326, Important)

* GRO (Generic Receive Offload) fields could be left in an inconsistent state. An attacker on the local network could use this flaw to cause a denial of service. GRO is enabled by default in all network drivers that support it. (CVE-2011-2723, Moderate)

* IPv4 and IPv6 protocol sequence number and fragment ID generation could allow a man-in-the-middle attacker to inject packets and possibly hijack connections. Protocol sequence numbers and fragment IDs are now more random. (CVE-2011-3188, Moderate)

* A flaw in the FUSE (Filesystem in Userspace) implementation could allow a local user in the fuse group who has access to mount a FUSE file system to cause a denial of service. (CVE-2011-3353, Moderate)

* A flaw in the b43 driver. If a system had an active wireless interface that uses the b43 driver, an attacker able to send a specially crafted frame to that interface could cause a denial of service. (CVE-2011-3359, Moderate)

* A flaw in the way CIFS shares with DFS referrals at their root were handled could allow an attacker on the local network, who is able to deploy a malicious CIFS server, to create a CIFS network share that, when mounted, would cause the client system to crash. (CVE-2011-3363, Moderate)

* A flaw in the m_stop() implementation could allow a local, unprivileged user to trigger a denial of service. (CVE-2011-3637, Moderate)

* Flaws in ghash_update() and ghash_final() could allow a local, unprivileged user to cause a denial of service. (CVE-2011-4081, Moderate)

* A flaw in the key management facility could allow a local, unprivileged user to cause a denial of service via the keyctl utility.
(CVE-2011-4110, Moderate)

* A flaw in the Journaling Block Device (JBD) could allow a local attacker to crash the system by mounting a specially crafted ext3 or ext4 disk. (CVE-2011-4132, Moderate)

* A flaw in the way memory containing security-related data was handled in tpm_read() could allow a local, unprivileged user to read the results of a previously run TPM command. (CVE-2011-1162, Low)

* I/O statistics from the taskstats subsystem could be read without any restrictions, which could allow a local, unprivileged user to gather confidential information, such as the length of a password used in a process. (CVE-2011-2494, Low)

* Flaws in tpacket_rcv() and packet_recvmsg() could allow a local, unprivileged user to leak information to user-space. (CVE-2011-2898, Low)

Red Hat would like to thank Darren Lavender for reporting CVE-2011-3191; Brent Meshier for reporting CVE-2011-2723; Dan Kaminsky for reporting CVE-2011-3188; Yogesh Sharma for reporting CVE-2011-3363; Nick Bowler for reporting CVE-2011-4081; Peter Huewe for reporting CVE-2011-1162; and Vasiliy Kulikov of Openwall for reporting CVE-2011-2494.

This update also fixes the following bugs :

* Previously, a mismatch in the build-id of the kernel-rt and the one in the related debuginfo package caused failures in SystemTap and perf. (BZ#768413)

* IBM x3650m3 systems were not able to boot the MRG Realtime kernel because they require a pmcraid driver that was not available. The pmcraid driver is included in this update. (BZ#753992)

Users should upgrade to these updated packages, which correct these issues. The system must be rebooted for this update to take effect.

The openSUSE 11.4 kernel was updated to fix bugs and security issues.

Following security issues have been fixed: CVE-2011-4604: If root does read() on a specific socket, it's possible to corrupt (kernel) memory over network, with an ICMP packet, if the B.A.T.M.A.N. mesh protocol is used.

CVE-2011-2699: Fernando Gont discovered that the IPv6 stack used predictable fragment identification numbers. A remote attacker could exploit this to exhaust network resources, leading to a denial of service.

CVE-2011-1173: A kernel information leak via ip6_tables was fixed.

CVE-2011-1172: A kernel information leak via ip6_tables netfilter was fixed.

CVE-2011-1171: A kernel information leak via ip_tables was fixed.

CVE-2011-1170: A kernel information leak via arp_tables was fixed.

CVE-2011-1080: A kernel information leak via netfilter was fixed.

CVE-2011-2213: The inet_diag_bc_audit function in net/ipv4/inet_diag.c in the Linux kernel did not properly audit INET_DIAG bytecode, which allowed local users to cause a denial of service (kernel infinite loop) via crafted INET_DIAG_REQ_BYTECODE instructions in a netlink message, as demonstrated by an INET_DIAG_BC_JMP instruction with a zero yes value, a different vulnerability than CVE-2010-3880.

CVE-2011-2534: Buffer overflow in the clusterip_proc_write function in net/ipv4/netfilter/ipt_CLUSTERIP.c in the Linux kernel might have allowed local users to cause a denial of service or have unspecified other impact via a crafted write operation, related to string data that lacks a terminating '0' character.

CVE-2011-1770: Integer underflow in the dccp_parse_options function (net/dccp/options.c) in the Linux kernel allowed remote attackers to cause a denial of service via a Datagram Congestion Control Protocol (DCCP) packet with an invalid feature options length, which triggered a buffer over-read.

CVE-2011-2723: The skb_gro_header_slow function in include/linux/netdevice.h in the Linux kernel, when Generic Receive Offload (GRO) is enabled, reset certain fields in incorrect situations, which allowed remote attackers to cause a denial of service (system crash) via crafted network traffic.

CVE-2011-2898: A kernel information leak in the AF_PACKET protocol was fixed which might have allowed local attackers to read kernel memory.

CVE-2011-4087: A local denial of service when using bridged networking via a flood ping was fixed.

CVE-2011-2203: A NULL ptr dereference on mounting corrupt hfs filesystems was fixed which could be used by local attackers to crash the kernel.

CVE-2011-4081: Using the crypto interface a local user could Oops the kernel by writing to a AF_ALG socket.

The openSUSE 11.3 kernel was updated to fix various bugs and security issues.

Following security issues have been fixed: CVE-2011-4604: If root does read() on a specific socket, it's possible to corrupt (kernel) memory over network, with an ICMP packet, if the B.A.T.M.A.N. mesh protocol is used.

CVE-2011-2525: A flaw allowed the tc_fill_qdisc() function in the Linux kernels packet scheduler API implementation to be called on built-in qdisc structures. A local, unprivileged user could have used this flaw to trigger a NULL pointer dereference, resulting in a denial of service.

CVE-2011-2699: Fernando Gont discovered that the IPv6 stack used predictable fragment identification numbers. A remote attacker could exploit this to exhaust network resources, leading to a denial of service.

CVE-2011-2213: The inet_diag_bc_audit function in net/ipv4/inet_diag.c in the Linux kernel did not properly audit INET_DIAG bytecode, which allowed local users to cause a denial of service (kernel infinite loop) via crafted INET_DIAG_REQ_BYTECODE instructions in a netlink message, as demonstrated by an INET_DIAG_BC_JMP instruction with a zero yes value, a different vulnerability than CVE-2010-3880.

CVE-2011-1576: The Generic Receive Offload (GRO) implementation in the Linux kernel allowed remote attackers to cause a denial of service via crafted VLAN packets that are processed by the napi_reuse_skb function, leading to (1) a memory leak or (2) memory corruption, a different vulnerability than CVE-2011-1478.

CVE-2011-2534: Buffer overflow in the clusterip_proc_write function in net/ipv4/netfilter/ipt_CLUSTERIP.c in the Linux kernel might have allowed local users to cause a denial of service or have unspecified other impact via a crafted write operation, related to string data that lacks a terminating '\0' character.

CVE-2011-1770: Integer underflow in the dccp_parse_options function (net/dccp/options.c) in the Linux kernel allowed remote attackers to cause a denial of service via a Datagram Congestion Control Protocol (DCCP) packet with an invalid feature options length, which triggered a buffer over-read.

CVE-2011-2723: The skb_gro_header_slow function in include/linux/netdevice.h in the Linux kernel, when Generic Receive Offload (GRO) is enabled, reset certain fields in incorrect situations, which allowed remote attackers to cause a denial of service (system crash) via crafted network traffic.

CVE-2011-2898: A kernel information leak in the AF_PACKET protocol was fixed which might have allowed local attackers to read kernel memory.

CVE-2011-2203: A NULL ptr dereference on mounting corrupt hfs filesystems was fixed which could be used by local attackers to crash the kernel.

CVE-2011-4081: Using the crypto interface a local user could Oops the kernel by writing to a AF_ALG socket.

The skb_gro_header_slow function in include/linux/netdevice.h in the Linux kernel before 2.6.39.4, when Generic Receive Offload (GRO) is enabled, resets certain fields in incorrect situations, which allows remote attackers to cause a denial of service (system crash) via crafted network traffic.

Race condition in the ecryptfs_mount function in fs/ecryptfs/main.c in the eCryptfs subsystem in the Linux kernel before 3.1 allows local users to bypass intended file permissions via a mount.ecryptfs_private mount with a mismatched uid.

The (1) IPv4 and (2) IPv6 implementations in the Linux kernel before 3.1 use a modified MD4 algorithm to generate sequence numbers and Fragment Identification values, which makes it easier for remote attackers to cause a denial of service (disrupted networking) or hijack network sessions by predicting these values and sending crafted packets.

Integer signedness error in the CIFSFindNext function in fs/cifs/cifssmb.c in the Linux kernel before 3.1 allows remote CIFS servers to cause a denial of service (memory corruption) or possibly have unspecified other impact via a large length value in a response to a read request for a directory.

The Performance Events subsystem in the Linux kernel before 3.1 does not properly handle event overflows associated with PERF_COUNT_SW_CPU_CLOCK events, which allows local users to cause a denial of service (system hang) via a crafted application.

The remote Oracle Linux 5 / 6 host has packages installed that are affected by multiple vulnerabilities as referenced in the ELSA-2011-2029 advisory.

    - af_packet: prevent information leak {CVE-2011-2898}
    - gro: Only reset frag0 when skb can be pulled {CVE-2011-2723}
    - vm: fix vm_pgoff wrap in stack expansion {CVE-2011-2496}
    - vm: fix vm_pgoff wrap in upward expansion {CVE-2011-2496}
    - taskstats: don't allow duplicate entries in listener mode {CVE-2011-2484}

Tenable has extracted the preceding description block directly from the Oracle Linux security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote Oracle Linux 5 host has packages installed that are affected by multiple vulnerabilities as referenced in the ELSA-2011-1386 advisory.

    - Revert: [xen] passthrough: block VT-d MSI trap injection (Paolo Bonzini) [716301 716302] {CVE-2011-1898}
    - [net] bridge: fix use after free in __br_deliver (Amerigo Wang) [730949 703045] {CVE-2011-2942}
    - [misc] remove div_long_long_rem (Prarit Bhargava) [732879 732614] {CVE-2011-3209}
    - [net] be2net: fix crash receiving non-member VLAN packets (Ivan Vecera) [736430 730239] {CVE-2011-3347}
    - [net] be2net: Use NTWK_RX_FILTER command for promiscous mode (Ivan Vecera) [736430 730239]     {CVE-2011-3347}
    - [net] be2net: non-member vlan pkts not received in promisc mode (Ivan Vecera) [736430 730239]     {CVE-2011-3347}
    - [net] be2net: remove bogus unlikely on vlan check (Ivan Vecera) [736430 730239] {CVE-2011-3347}
    - [net] Compute protocol seq numbers and fragment IDs using MD5 (Jiri Pirko) [732662 732663]     {CVE-2011-3188}
    - [crypto] Move md5_transform to lib/md5.c (Jiri Pirko) [732662 732663] {CVE-2011-3188}
    - [mm] avoid wrapping vm_pgoff in mremap and stack expansion (Jerome Marchand) [716543 716544]     {CVE-2011-2496}
    - [fs] ecryptfs: Add mount option to check uid of mounting device (Eric Sandeen) [731173 731174]     {CVE-2011-1833}
    - [net] ipv6: make fragment identifications less predictable (Jiri Pirko) [723430 723431] {CVE-2011-2699}
    - [net] ipv6: Remove unused skb argument of ipv6_select_ident (Jiri Pirko) [723430 723431] {CVE-2011-2699}
    - [misc] taskstats: don't allow duplicate entries in listener mode (Jerome Marchand) [715449 715450]     {CVE-2011-2484}
    - [net] gro: Only reset frag0 when skb can be pulled (Herbert Xu) [726553 679682] {CVE-2011-2723}
    - [xen] passthrough: block VT-d MSI trap injection (Paolo Bonzini) [716301 716302] {CVE-2011-1898}
    - [xen] iommu: disable bus-mastering on hw that causes IOMMU fault (Laszlo Ersek) [730342 730343]     {CVE-2011-3131}
    - [usb] auerswald: fix buffer overflow (Don Zickus) [722395 722396] {CVE-2009-4067}
    - [fs] cifs: fix possible memory corruption in CIFSFindNext (Jeff Layton) [732870 736654 732869 732471]     {CVE-2011-3191}
    - [fs] cifs: revert special handling for matching krb5 sessions (Jeff Layton) [697395 697396]     {CVE-2011-1585}
    - [fs] cifs: check for NULL session password (Jeff Layton) [697395 697396] {CVE-2011-1585}
    - [fs] cifs: fix NULL pointer dereference in cifs_find_smb_ses (Jeff Layton) [697395 697396]     {CVE-2011-1585}
    - [fs] cifs: clean up cifs_find_smb_ses (Jeff Layton) [697395 697396] {CVE-2011-1585}
    - [char] tpm: Fix uninitialized usage of data buffer (Stanislaw Gruszka) [684672 684673] {CVE-2011-1160}
    - [fs] ext4: Fix max size and logical block counting of extent file (Lukas Czerner) [722562 722563]     {CVE-2011-2695}

Tenable has extracted the preceding description block directly from the Oracle Linux security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote Oracle Linux 6 host has packages installed that are affected by multiple vulnerabilities as referenced in the ELSA-2011-1350 advisory.

  - The tpm_open function in drivers/char/tpm/tpm.c in the Linux kernel before 2.6.39 does not initialize a     certain buffer, which allows local users to obtain potentially sensitive information from kernel memory     via unspecified vectors. (CVE-2011-1160)

  - Integer overflow in the agp_generic_insert_memory function in drivers/char/agp/generic.c in the Linux     kernel before 2.6.38.5 allows local users to gain privileges or cause a denial of service (system crash)     via a crafted AGPIOC_BIND agp_ioctl ioctl call. (CVE-2011-1745)

  - Multiple integer overflows in the (1) agp_allocate_memory and (2) agp_create_user_memory functions in     drivers/char/agp/generic.c in the Linux kernel before 2.6.38.5 allow local users to trigger buffer     overflows, and consequently cause a denial of service (system crash) or possibly have unspecified other     impact, via vectors related to calls that specify a large number of memory pages. (CVE-2011-1746)

  - Race condition in the ecryptfs_mount function in fs/ecryptfs/main.c in the eCryptfs subsystem in the Linux     kernel before 3.1 allows local users to bypass intended file permissions via a mount.ecryptfs_private     mount with a mismatched uid. (CVE-2011-1833)

  - The agp_generic_remove_memory function in drivers/char/agp/generic.c in the Linux kernel before 2.6.38.5     does not validate a certain start parameter, which allows local users to gain privileges or cause a denial     of service (system crash) via a crafted AGPIOC_UNBIND agp_ioctl ioctl call, a different vulnerability than     CVE-2011-1745. (CVE-2011-2022)

  - The add_del_listener function in kernel/taskstats.c in the Linux kernel 2.6.39.1 and earlier does not     prevent multiple registrations of exit handlers, which allows local users to cause a denial of service     (memory and CPU consumption), and bypass the OOM Killer, via a crafted application. (CVE-2011-2484)

  - Integer overflow in the vma_to_resize function in mm/mremap.c in the Linux kernel before 2.6.39 allows     local users to cause a denial of service (BUG_ON and system crash) via a crafted mremap system call that     expands a memory mapping. (CVE-2011-2496)

  - The x86_assign_hw_event function in arch/x86/kernel/cpu/perf_event.c in the Performance Events subsystem     in the Linux kernel before 2.6.39 does not properly calculate counter values, which allows local users to     cause a denial of service (panic) via the perf program. (CVE-2011-2521)

  - The skb_gro_header_slow function in include/linux/netdevice.h in the Linux kernel before 2.6.39.4, when     Generic Receive Offload (GRO) is enabled, resets certain fields in incorrect situations, which allows     remote attackers to cause a denial of service (system crash) via crafted network traffic. (CVE-2011-2723)

  - net/packet/af_packet.c in the Linux kernel before 2.6.39.3 does not properly restrict user-space access to     certain packet data structures associated with VLAN Tag Control Information, which allows local users to     obtain potentially sensitive information via a crafted application. (CVE-2011-2898)

  - The Performance Events subsystem in the Linux kernel before 3.1 does not properly handle event overflows     associated with PERF_COUNT_SW_CPU_CLOCK events, which allows local users to cause a denial of service     (system hang) via a crafted application. (CVE-2011-2918)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The remote Redhat Enterprise Linux 5 host has packages installed that are affected by a vulnerability as referenced in the RHSA-2011:1321 advisory.

  - kernel: gro: only reset frag0 when skb can be pulled (CVE-2011-2723)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The kernel packages contain the Linux kernel, the core of any Linux operating system.

Security fixes :

  - The maximum file offset handling for ext4 file systems     could allow a local, unprivileged user to cause a denial     of service. (CVE-2011-2695, Important)

  - IPv6 fragment identification value generation could     allow a remote attacker to disrupt a target system's     networking, preventing legitimate users from accessing     its services. (CVE-2011-2699, Important)

  - A malicious CIFS (Common Internet File System) server     could send a specially crafted response to a directory     read request that would result in a denial of service or     privilege escalation on a system that has a CIFS share     mounted. (CVE-2011-3191, Important)

  - A local attacker could use mount.ecryptfs_private to     mount (and then access) a directory they would otherwise     not have access to. Note: To correct this issue, a     ecryptfs-utils update must also be installed.
    (CVE-2011-1833, Moderate)

  - A flaw in the taskstats subsystem could allow a local,     unprivileged user to cause excessive CPU time and memory     use. (CVE-2011-2484, Moderate)

  - Mapping expansion handling could allow a local,     unprivileged user to cause a denial of service.
    (CVE-2011-2496, Moderate)

  - GRO (Generic Receive Offload) fields could be left in an     inconsistent state. An attacker on the local network     could use this flaw to cause a denial of service. GRO is     enabled by default in all network drivers that support     it. (CVE-2011-2723, Moderate)

  - A previous update introduced a regression in the     Ethernet bridge implementation. If a system had an     interface in a bridge, and an attacker on the local     network could send packets to that interface, they could     cause a denial of service on that system. Xen hypervisor     and KVM (Kernel-based Virtual Machine) hosts often     deploy bridge interfaces. (CVE-2011-2942, Moderate)

  - A flaw in the Xen hypervisor IOMMU error handling     implementation could allow a privileged guest user,     within a guest operating system that has direct control     of a PCI device, to cause performance degradation on the     host and possibly cause it to hang. (CVE-2011-3131,     Moderate)

  - IPv4 and IPv6 protocol sequence number and fragment ID     generation could allow a man-in-the-middle attacker to     inject packets and possibly hijack connections. Protocol     sequence number and fragment IDs are now more random.
    (CVE-2011-3188, Moderate)

  - A flaw in the kernel's clock implementation could allow     a local, unprivileged user to cause a denial of service.
    (CVE-2011-3209, Moderate)

  - Non-member VLAN (virtual LAN) packet handling for     interfaces in promiscuous mode and also using the be2net     driver could allow an attacker on the local network to     cause a denial of service. (CVE-2011-3347, Moderate)

  - A flaw in the auerswald USB driver could allow a local,     unprivileged user to cause a denial of service or     escalate their privileges by inserting a specially     crafted USB device. (CVE-2009-4067, Low)

  - A flaw in the Trusted Platform Module (TPM)     implementation could allow a local, unprivileged user to     leak information to user space. (CVE-2011-1160, Low)

  - A local, unprivileged user could possibly mount a CIFS     share that requires authentication without knowing the     correct password if the mount was already mounted by     another local user. (CVE-2011-1585, Low)

The kernel packages contain the Linux kernel, the core of any Linux operating system.

This update fixes the following security issues :

  - Flaws in the AGPGART driver implementation when handling     certain IOCTL commands could allow a local user to cause     a denial of service or escalate their privileges.
    (CVE-2011-1745, CVE-2011-2022, Important)

  - An integer overflow flaw in agp_allocate_memory() could     allow a local user to cause a denial of service or     escalate their privileges. (CVE-2011-1746, Important)

  - A race condition flaw was found in the Linux kernel's     eCryptfs implementation. A local attacker could use the     mount.ecryptfs_private utility to mount (and then     access) a directory they would otherwise not have access     to. Note: To correct this issue, a previous     ecryptfs-utils update, which provides the user-space     part of the fix, must also be installed. (CVE-2011-1833,     Moderate)

  - A denial of service flaw was found in the way the     taskstats subsystem handled the registration of process     exit handlers. A local, unprivileged user could register     an unlimited amount of these handlers, leading to     excessive CPU time and memory use. (CVE-2011-2484,     Moderate)

  - A flaw was found in the way mapping expansions were     handled. A local, unprivileged user could use this flaw     to cause a wrapping condition, triggering a denial of     service. (CVE-2011-2496, Moderate)

  - A flaw was found in the Linux kernel's Performance     Events implementation. It could falsely lead the NMI     (Non-Maskable Interrupt) Watchdog to detect a lockup and     panic the system. A local, unprivileged user could use     this flaw to cause a denial of service (kernel panic)     using the perf tool. (CVE-2011-2521, Moderate)

  - A flaw in skb_gro_header_slow() in the Linux kernel     could lead to GRO (Generic Receive Offload) fields being     left in an inconsistent state. An attacker on the local     network could use this flaw to trigger a denial of     service. GRO is enabled by default in all network     drivers that support it. (CVE-2011-2723, Moderate)

  - A flaw was found in the way the Linux kernel's     Performance Events implementation handled     PERF_COUNT_SW_CPU_CLOCK counter overflow. A local,     unprivileged user could use this flaw to cause a denial     of service. (CVE-2011-2918, Moderate)

  - A flaw was found in the Linux kernel's Trusted Platform     Module (TPM) implementation. A local, unprivileged user     could use this flaw to leak information to user-space.
    (CVE-2011-1160, Low)

  - Flaws were found in the tpacket_rcv() and     packet_recvmsg() functions in the Linux kernel. A local,     unprivileged user could use these flaws to leak     information to user-space. (CVE-2011-2898, Low)

This update also fixes various bugs and adds one enhancement.
Documentation for these changes will be available shortly from the Technical Notes document linked to in the References section.

Users should upgrade to these updated packages, which contain backported patches to correct these issues, and fix the bugs and add the enhancement noted in the Technical Notes. The system must be rebooted for this update to take effect.

It was discovered that the /proc filesystem did not correctly handle permission changes when programs executed. A local attacker could hold open files to examine details about programs running with higher privileges, potentially increasing the chances of exploiting additional vulnerabilities. (CVE-2011-1020)

Vasiliy Kulikov discovered that the Bluetooth stack did not correctly clear memory. A local attacker could exploit this to read kernel stack memory, leading to a loss of privacy. (CVE-2011-1078)

Vasiliy Kulikov discovered that the Bluetooth stack did not correctly check that device name strings were NULL terminated. A local attacker could exploit this to crash the system, leading to a denial of service, or leak contents of kernel stack memory, leading to a loss of privacy. (CVE-2011-1079)

Vasiliy Kulikov discovered that bridge network filtering did not check that name fields were NULL terminated. A local attacker could exploit this to leak contents of kernel stack memory, leading to a loss of privacy. (CVE-2011-1080)

Johan Hovold discovered that the DCCP network stack did not correctly handle certain packet combinations. A remote attacker could send specially crafted network traffic that would crash the system, leading to a denial of service. (CVE-2011-1093)

Peter Huewe discovered that the TPM device did not correctly initialize memory. A local attacker could exploit this to read kernel heap memory contents, leading to a loss of privacy. (CVE-2011-1160)

Dan Rosenberg discovered that the IRDA subsystem did not correctly check certain field sizes. If a system was using IRDA, a remote attacker could send specially crafted traffic to crash the system or gain root privileges. (CVE-2011-1180)

Ryan Sweat discovered that the GRO code did not correctly validate memory. In some configurations on systems using VLANs, a remote attacker could send specially crafted traffic to crash the system, leading to a denial of service. (CVE-2011-1478)

It was discovered that the security fix for CVE-2010-4250 introduced a regression. A remote attacker could exploit this to crash the system, leading to a denial of service. (CVE-2011-1479)

Dan Rosenberg discovered that the X.25 Rose network stack did not correctly handle certain fields. If a system was running with Rose enabled, a remote attacker could send specially crafted traffic to gain root privileges. (CVE-2011-1493)

It was discovered that the Stream Control Transmission Protocol (SCTP) implementation incorrectly calculated lengths. If the net.sctp.addip_enable variable was turned on, a remote attacker could send specially crafted traffic to crash the system. (CVE-2011-1573)

Ryan Sweat discovered that the kernel incorrectly handled certain VLAN packets. On some systems, a remote attacker could send specially crafted traffic to crash the system, leading to a denial of service.
(CVE-2011-1576)

Timo Warns discovered that the GUID partition parsing routines did not correctly validate certain structures. A local attacker with physical access could plug in a specially crafted block device to crash the system, leading to a denial of service. (CVE-2011-1577)

Phil Oester discovered that the network bonding system did not correctly handle large queues. On some systems, a remote attacker could send specially crafted traffic to crash the system, leading to a denial of service. (CVE-2011-1581)

It was discovered that CIFS incorrectly handled authentication. When a user had a CIFS share mounted that required authentication, a local user could mount the same share without knowing the correct password.
(CVE-2011-1585)

It was discovered that the GRE protocol incorrectly handled netns initialization. A remote attacker could send a packet while the ip_gre module was loading, and crash the system, leading to a denial of service. (CVE-2011-1767)

It was discovered that the IP/IP protocol incorrectly handled netns initialization. A remote attacker could send a packet while the ipip module was loading, and crash the system, leading to a denial of service. (CVE-2011-1768)

Ben Greear discovered that CIFS did not correctly handle direct I/O. A local attacker with access to a CIFS partition could exploit this to crash the system, leading to a denial of service. (CVE-2011-1771)

Timo Warns discovered that the EFI GUID partition table was not correctly parsed. A physically local attacker that could insert mountable devices could exploit this to crash the system or possibly gain root privileges. (CVE-2011-1776)

Vasiliy Kulikov and Dan Rosenberg discovered that ecryptfs did not correctly check the origin of mount points. A local attacker could exploit this to trick the system into unmounting arbitrary mount points, leading to a denial of service. (CVE-2011-1833)

Ben Hutchings reported a flaw in the kernel's handling of corrupt LDM partitions. A local user could exploit this to cause a denial of service or escalate privileges. (CVE-2011-2182)

Dan Rosenberg discovered that the IPv4 diagnostic routines did not correctly validate certain requests. A local attacker could exploit this to consume CPU resources, leading to a denial of service.
(CVE-2011-2213)

It was discovered that an mmap() call with the MAP_PRIVATE flag on '/dev/zero' was incorrectly handled. A local attacker could exploit this to crash the system, leading to a denial of service.
(CVE-2011-2479)

Vasiliy Kulikov discovered that taskstats listeners were not correctly handled. A local attacker could exploit this to exhaust memory and CPU resources, leading to a denial of service. (CVE-2011-2484)

It was discovered that Bluetooth l2cap and rfcomm did not correctly initialize structures. A local attacker could exploit this to read portions of the kernel stack, leading to a loss of privacy.
(CVE-2011-2492)

Sami Liedes discovered that ext4 did not correctly handle missing root inodes. A local attacker could trigger the mount of a specially crafted filesystem to cause the system to crash, leading to a denial of service. (CVE-2011-2493)

Robert Swiecki discovered that mapping extensions were incorrectly handled. A local attacker could exploit this to crash the system, leading to a denial of service. (CVE-2011-2496)

Dan Rosenberg discovered that the Bluetooth stack incorrectly handled certain L2CAP requests. If a system was using Bluetooth, a remote attacker could send specially crafted traffic to crash the system or gain root privileges. (CVE-2011-2497)

Ben Pfaff discovered that Classless Queuing Disciplines (qdiscs) were being incorrectly handled. A local attacker could exploit this to crash the system, leading to a denial of service. (CVE-2011-2525)

It was discovered that GFS2 did not correctly check block sizes. A local attacker could exploit this to crash the system, leading to a denial of service. (CVE-2011-2689)

It was discovered that the EXT4 filesystem contained multiple off-by-one flaws. A local attacker could exploit this to crash the system, leading to a denial of service. (CVE-2011-2695)

Fernando Gont discovered that the IPv6 stack used predictable fragment identification numbers. A remote attacker could exploit this to exhaust network resources, leading to a denial of service.
(CVE-2011-2699)

Mauro Carvalho Chehab discovered that the si4713 radio driver did not correctly check the length of memory copies. If this hardware was available, a local attacker could exploit this to crash the system or gain root privileges. (CVE-2011-2700)

Herbert Xu discovered that certain fields were incorrectly handled when Generic Receive Offload (CVE-2011-2723)

The performance counter subsystem did not correctly handle certain counters. A local attacker could exploit this to crash the system, leading to a denial of service. (CVE-2011-2918)

Time Warns discovered that long symlinks were incorrectly handled on Be filesystems. A local attacker could exploit this with a malformed Be filesystem and crash the system, leading to a denial of service.
(CVE-2011-2928)

Qianfeng Zhang discovered that the bridge networking interface incorrectly handled certain network packets. A remote attacker could exploit this to crash the system, leading to a denial of service.
(CVE-2011-2942)

Dan Kaminsky discovered that the kernel incorrectly handled random sequence number generation. An attacker could use this flaw to possibly predict sequence numbers and inject packets. (CVE-2011-3188)

Darren Lavender discovered that the CIFS client incorrectly handled certain large values. A remote attacker with a malicious server could exploit this to crash the system or possibly execute arbitrary code as the root user. (CVE-2011-3191)

Yasuaki Ishimatsu discovered a flaw in the kernel's clock implementation. A local unprivileged attacker could exploit this causing a denial of service. (CVE-2011-3209)

Yogesh Sharma discovered that CIFS did not correctly handle UNCs that had no prefixpaths. A local attacker with access to a CIFS partition could exploit this to crash the system, leading to a denial of service. (CVE-2011-3363)

A flaw was discovered in the Linux kernel's AppArmor security interface when invalid information was written to it. An unprivileged local user could use this to cause a denial of service on the system.
(CVE-2011-3619)

A flaw was found in the Linux kernel's /proc/*/*map* interface. A local, unprivileged user could exploit this flaw to cause a denial of service. (CVE-2011-3637)

Scot Doyle discovered that the bridge networking interface incorrectly handled certain network packets. A remote attacker could exploit this to crash the system, leading to a denial of service. (CVE-2011-4087)

A bug was found in the way headroom check was performed in udp6_ufo_fragment() function. A remote attacker could use this flaw to crash the system. (CVE-2011-4326)

Ben Hutchings discovered several flaws in the Linux Rose (X.25 PLP) layer. A local user or a remote user on an X.25 network could exploit these flaws to execute arbitrary code as root. (CVE-2011-4914).

Note that Tenable Network Security has extracted the preceding description block directly from the Ubuntu security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

Dan Rosenberg discovered that the IPv4 diagnostic routines did not correctly validate certain requests. A local attacker could exploit this to consume CPU resources, leading to a denial of service.
(CVE-2011-2213)

Dan Rosenberg discovered that the Bluetooth stack incorrectly handled certain L2CAP requests. If a system was using Bluetooth, a remote attacker could send specially crafted traffic to crash the system or gain root privileges. (CVE-2011-2497)

It was discovered that the EXT4 filesystem contained multiple off-by-one flaws. A local attacker could exploit this to crash the system, leading to a denial of service. (CVE-2011-2695)

Mauro Carvalho Chehab discovered that the si4713 radio driver did not correctly check the length of memory copies. If this hardware was available, a local attacker could exploit this to crash the system or gain root privileges. (CVE-2011-2700)

Herbert Xu discovered that certain fields were incorrectly handled when Generic Receive Offload (CVE-2011-2723)

Time Warns discovered that long symlinks were incorrectly handled on Be filesystems. A local attacker could exploit this with a malformed Be filesystem and crash the system, leading to a denial of service.
(CVE-2011-2928)

Dan Kaminsky discovered that the kernel incorrectly handled random sequence number generation. An attacker could use this flaw to possibly predict sequence numbers and inject packets. (CVE-2011-3188)

Darren Lavender discovered that the CIFS client incorrectly handled certain large values. A remote attacker with a malicious server could exploit this to crash the system or possibly execute arbitrary code as the root user. (CVE-2011-3191).

Note that Tenable Network Security has extracted the preceding description block directly from the Ubuntu security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

It was discovered that the Stream Control Transmission Protocol (SCTP) implementation incorrectly calculated lengths. If the net.sctp.addip_enable variable was turned on, a remote attacker could send specially crafted traffic to crash the system. (CVE-2011-1573)

Ryan Sweat discovered that the kernel incorrectly handled certain VLAN packets. On some systems, a remote attacker could send specially crafted traffic to crash the system, leading to a denial of service.
(CVE-2011-1576)

Timo Warns discovered that the EFI GUID partition table was not correctly parsed. A physically local attacker that could insert mountable devices could exploit this to crash the system or possibly gain root privileges. (CVE-2011-1776)

Dan Rosenberg discovered that the IPv4 diagnostic routines did not correctly validate certain requests. A local attacker could exploit this to consume CPU resources, leading to a denial of service.
(CVE-2011-2213)

Vasiliy Kulikov discovered that taskstats did not enforce access restrictions. A local attacker could exploit this to read certain information, leading to a loss of privacy. (CVE-2011-2494)

Vasiliy Kulikov discovered that /proc/PID/io did not enforce access restrictions. A local attacker could exploit this to read certain information, leading to a loss of privacy. (CVE-2011-2495)

Robert Swiecki discovered that mapping extensions were incorrectly handled. A local attacker could exploit this to crash the system, leading to a denial of service. (CVE-2011-2496)

Dan Rosenberg discovered that the Bluetooth stack incorrectly handled certain L2CAP requests. If a system was using Bluetooth, a remote attacker could send specially crafted traffic to crash the system or gain root privileges. (CVE-2011-2497)

It was discovered that the wireless stack incorrectly verified SSID lengths. A local attacker could exploit this to cause a denial of service or gain root privileges. (CVE-2011-2517)

Ben Pfaff discovered that Classless Queuing Disciplines (qdiscs) were being incorrectly handled. A local attacker could exploit this to crash the system, leading to a denial of service. (CVE-2011-2525)

It was discovered that the EXT4 filesystem contained multiple off-by-one flaws. A local attacker could exploit this to crash the system, leading to a denial of service. (CVE-2011-2695)

Herbert Xu discovered that certain fields were incorrectly handled when Generic Receive Offload (CVE-2011-2723)

Christian Ohm discovered that the perf command looks for configuration files in the current directory. If a privileged user were tricked into running perf in a directory containing a malicious configuration file, an attacker could run arbitrary commands and possibly gain privileges. (CVE-2011-2905)

Vasiliy Kulikov discovered that the Comedi driver did not correctly clear memory. A local attacker could exploit this to read kernel stack memory, leading to a loss of privacy. (CVE-2011-2909)

Time Warns discovered that long symlinks were incorrectly handled on Be filesystems. A local attacker could exploit this with a malformed Be filesystem and crash the system, leading to a denial of service.
(CVE-2011-2928)

Dan Kaminsky discovered that the kernel incorrectly handled random sequence number generation. An attacker could use this flaw to possibly predict sequence numbers and inject packets. (CVE-2011-3188)

Darren Lavender discovered that the CIFS client incorrectly handled certain large values. A remote attacker with a malicious server could exploit this to crash the system or possibly execute arbitrary code as the root user. (CVE-2011-3191)

Yogesh Sharma discovered that CIFS did not correctly handle UNCs that had no prefixpaths. A local attacker with access to a CIFS partition could exploit this to crash the system, leading to a denial of service. (CVE-2011-3363)

The remote Redhat Enterprise Linux 5 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2011:1386 advisory.

  - kernel: usb: buffer overflow in auerswald_probe() (CVE-2009-4067)

  - kernel: tpm infoleaks (CVE-2011-1160)

  - kernel: cifs session reuse (CVE-2011-1585)

  - kernel: ecryptfs: mount source TOCTOU race (CVE-2011-1833)

  - kernel: taskstats: duplicate entries in listener mode can lead to DoS (CVE-2011-2484)

  - kernel: mm: avoid wrapping vm_pgoff in mremap() and stack expansions (CVE-2011-2496)

  - kernel: ext4: kernel panic when writing data to the last block of sparse file (CVE-2011-2695)

  - kernel: ipv6: make fragment identifications less predictable (CVE-2011-2699)

  - kernel: gro: only reset frag0 when skb can be pulled (CVE-2011-2723)

  - kernel: bridge: null pointer dereference in __br_deliver (CVE-2011-2942)

  - kernel: xen: IOMMU fault livelock (CVE-2011-3131)

  - kernel: net: improve sequence number generation (CVE-2011-3188)

  - kernel: cifs: signedness issue in CIFSFindNext() (CVE-2011-3191)

  - kernel: panic occurs when clock_gettime() is called (CVE-2011-3209)

  - kernel: be2net: promiscuous mode and non-member VLAN packets DoS (CVE-2011-3347)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

Updated kernel packages that fix multiple security issues, several bugs, and add one enhancement are now available for Red Hat Enterprise Linux 5.

The Red Hat Security Response Team has rated this update as having important security impact. Common Vulnerability Scoring System (CVSS) base scores, which give detailed severity ratings, are available for each vulnerability from the CVE links in the References section.

The kernel packages contain the Linux kernel, the core of any Linux operating system.

Security fixes :

* The maximum file offset handling for ext4 file systems could allow a local, unprivileged user to cause a denial of service. (CVE-2011-2695, Important)

* IPv6 fragment identification value generation could allow a remote attacker to disrupt a target system's networking, preventing legitimate users from accessing its services. (CVE-2011-2699, Important)

* A malicious CIFS (Common Internet File System) server could send a specially crafted response to a directory read request that would result in a denial of service or privilege escalation on a system that has a CIFS share mounted. (CVE-2011-3191, Important)

* A local attacker could use mount.ecryptfs_private to mount (and then access) a directory they would otherwise not have access to. Note: To correct this issue, the RHSA-2011:1241 ecryptfs-utils update must also be installed. (CVE-2011-1833, Moderate)

* A flaw in the taskstats subsystem could allow a local, unprivileged user to cause excessive CPU time and memory use. (CVE-2011-2484, Moderate)

* Mapping expansion handling could allow a local, unprivileged user to cause a denial of service. (CVE-2011-2496, Moderate)

* GRO (Generic Receive Offload) fields could be left in an inconsistent state. An attacker on the local network could use this flaw to cause a denial of service. GRO is enabled by default in all network drivers that support it. (CVE-2011-2723, Moderate)

* RHSA-2011:1065 introduced a regression in the Ethernet bridge implementation. If a system had an interface in a bridge, and an attacker on the local network could send packets to that interface, they could cause a denial of service on that system. Xen hypervisor and KVM (Kernel-based Virtual Machine) hosts often deploy bridge interfaces. (CVE-2011-2942, Moderate)

* A flaw in the Xen hypervisor IOMMU error handling implementation could allow a privileged guest user, within a guest operating system that has direct control of a PCI device, to cause performance degradation on the host and possibly cause it to hang. (CVE-2011-3131, Moderate)

* IPv4 and IPv6 protocol sequence number and fragment ID generation could allow a man-in-the-middle attacker to inject packets and possibly hijack connections. Protocol sequence number and fragment IDs are now more random. (CVE-2011-3188, Moderate)

* A flaw in the kernel's clock implementation could allow a local, unprivileged user to cause a denial of service. (CVE-2011-3209, Moderate)

* Non-member VLAN (virtual LAN) packet handling for interfaces in promiscuous mode and also using the be2net driver could allow an attacker on the local network to cause a denial of service.
(CVE-2011-3347, Moderate)

* A flaw in the auerswald USB driver could allow a local, unprivileged user to cause a denial of service or escalate their privileges by inserting a specially crafted USB device. (CVE-2009-4067, Low)

* A flaw in the Trusted Platform Module (TPM) implementation could allow a local, unprivileged user to leak information to user space.
(CVE-2011-1160, Low)

* A local, unprivileged user could possibly mount a CIFS share that requires authentication without knowing the correct password if the mount was already mounted by another local user. (CVE-2011-1585, Low)

Red Hat would like to thank Fernando Gont for reporting CVE-2011-2699;
Darren Lavender for reporting CVE-2011-3191; the Ubuntu Security Team for reporting CVE-2011-1833; Vasiliy Kulikov of Openwall for reporting CVE-2011-2484; Robert Swiecki for reporting CVE-2011-2496; Brent Meshier for reporting CVE-2011-2723; Dan Kaminsky for reporting CVE-2011-3188; Yasuaki Ishimatsu for reporting CVE-2011-3209; Somnath Kotur for reporting CVE-2011-3347; Rafael Dominguez Vega for reporting CVE-2009-4067; and Peter Huewe for reporting CVE-2011-1160. The Ubuntu Security Team acknowledges Vasiliy Kulikov of Openwall and Dan Rosenberg as the original reporters of CVE-2011-1833.

Timo Warns discovered that the EFI GUID partition table was not correctly parsed. A physically local attacker that could insert mountable devices could exploit this to crash the system or possibly gain root privileges. (CVE-2011-1776)

Dan Rosenberg discovered that the IPv4 diagnostic routines did not correctly validate certain requests. A local attacker could exploit this to consume CPU resources, leading to a denial of service.
(CVE-2011-2213)

Dan Rosenberg discovered that the Bluetooth stack incorrectly handled certain L2CAP requests. If a system was using Bluetooth, a remote attacker could send specially crafted traffic to crash the system or gain root privileges. (CVE-2011-2497)

It was discovered that the EXT4 filesystem contained multiple off-by-one flaws. A local attacker could exploit this to crash the system, leading to a denial of service. (CVE-2011-2695)

Mauro Carvalho Chehab discovered that the si4713 radio driver did not correctly check the length of memory copies. If this hardware was available, a local attacker could exploit this to crash the system or gain root privileges. (CVE-2011-2700)

Herbert Xu discovered that certain fields were incorrectly handled when Generic Receive Offload (CVE-2011-2723)

Time Warns discovered that long symlinks were incorrectly handled on Be filesystems. A local attacker could exploit this with a malformed Be filesystem and crash the system, leading to a denial of service.
(CVE-2011-2928)

Dan Kaminsky discovered that the kernel incorrectly handled random sequence number generation. An attacker could use this flaw to possibly predict sequence numbers and inject packets. (CVE-2011-3188)

Darren Lavender discovered that the CIFS client incorrectly handled certain large values. A remote attacker with a malicious server could exploit this to crash the system or possibly execute arbitrary code as the root user. (CVE-2011-3191)

Ryan Sweat discovered that the kernel incorrectly handled certain VLAN packets. On some systems, a remote attacker could send specially crafted traffic to crash the system, leading to a denial of service.
(CVE-2011-1576)

Timo Warns discovered that the EFI GUID partition table was not correctly parsed. A physically local attacker that could insert mountable devices could exploit this to crash the system or possibly gain root privileges. (CVE-2011-1776)

Vasiliy Kulikov and Dan Rosenberg discovered that ecryptfs did not correctly check the origin of mount points. A local attacker could exploit this to trick the system into unmounting arbitrary mount points, leading to a denial of service. (CVE-2011-1833)

Dan Rosenberg discovered that the IPv4 diagnostic routines did not correctly validate certain requests. A local attacker could exploit this to consume CPU resources, leading to a denial of service.
(CVE-2011-2213)

Dan Rosenberg discovered that the Bluetooth stack incorrectly handled certain L2CAP requests. If a system was using Bluetooth, a remote attacker could send specially crafted traffic to crash the system or gain root privileges. (CVE-2011-2497)

Fernando Gont discovered that the IPv6 stack used predictable fragment identification numbers. A remote attacker could exploit this to exhaust network resources, leading to a denial of service.
(CVE-2011-2699)

Mauro Carvalho Chehab discovered that the si4713 radio driver did not correctly check the length of memory copies. If this hardware was available, a local attacker could exploit this to crash the system or gain root privileges. (CVE-2011-2700)

Herbert Xu discovered that certain fields were incorrectly handled when Generic Receive Offload (CVE-2011-2723)

The performance counter subsystem did not correctly handle certain counters. A local attacker could exploit this to crash the system, leading to a denial of service. (CVE-2011-2918)

Time Warns discovered that long symlinks were incorrectly handled on Be filesystems. A local attacker could exploit this with a malformed Be filesystem and crash the system, leading to a denial of service.
(CVE-2011-2928)

Darren Lavender discovered that the CIFS client incorrectly handled certain large values. A remote attacker with a malicious server could exploit this to crash the system or possibly execute arbitrary code as the root user. (CVE-2011-3191)

Gideon Naim discovered a flaw in the Linux kernel's handling VLAN 0 frames. An attacker on the local network could exploit this flaw to cause a denial of service. (CVE-2011-3593).

Note that Tenable Network Security has extracted the preceding description block directly from the Ubuntu security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

The remote Redhat Enterprise Linux 6 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2011:1350 advisory.

    The kernel packages contain the Linux kernel, the core of any Linux     operating system.

    This update fixes the following security issues:

    * Flaws in the AGPGART driver implementation when handling certain IOCTL     commands could allow a local user to cause a denial of service or escalate     their privileges. (CVE-2011-1745, CVE-2011-2022, Important)

    * An integer overflow flaw in agp_allocate_memory() could allow a local     user to cause a denial of service or escalate their privileges.
    (CVE-2011-1746, Important)

    * A race condition flaw was found in the Linux kernel's eCryptfs     implementation. A local attacker could use the mount.ecryptfs_private     utility to mount (and then access) a directory they would otherwise not     have access to. Note: To correct this issue, the RHSA-2011:1241     ecryptfs-utils update, which provides the user-space part of the fix, must     also be installed. (CVE-2011-1833, Moderate)

    * A denial of service flaw was found in the way the taskstats subsystem     handled the registration of process exit handlers. A local, unprivileged     user could register an unlimited amount of these handlers, leading to     excessive CPU time and memory use. (CVE-2011-2484, Moderate)

    * A flaw was found in the way mapping expansions were handled. A local,     unprivileged user could use this flaw to cause a wrapping condition,     triggering a denial of service. (CVE-2011-2496, Moderate)

    * A flaw was found in the Linux kernel's Performance Events implementation.
    It could falsely lead the NMI (Non-Maskable Interrupt) Watchdog to detect a     lockup and panic the system. A local, unprivileged user could use this flaw     to cause a denial of service (kernel panic) using the perf tool.
    (CVE-2011-2521, Moderate)

    * A flaw in skb_gro_header_slow() in the Linux kernel could lead to GRO     (Generic Receive Offload) fields being left in an inconsistent state. An     attacker on the local network could use this flaw to trigger a denial of     service. GRO is enabled by default in all network drivers that support it.
    (CVE-2011-2723, Moderate)

    * A flaw was found in the way the Linux kernel's Performance Events     implementation handled PERF_COUNT_SW_CPU_CLOCK counter overflow. A local,     unprivileged user could use this flaw to cause a denial of service.
    (CVE-2011-2918, Moderate)

    * A flaw was found in the Linux kernel's Trusted Platform Module (TPM)     implementation. A local, unprivileged user could use this flaw to leak     information to user-space. (CVE-2011-1160, Low)

    * Flaws were found in the tpacket_rcv() and packet_recvmsg() functions in     the Linux kernel. A local, unprivileged user could use these flaws to leak     information to user-space. (CVE-2011-2898, Low)

    Red Hat would like to thank Vasiliy Kulikov of Openwall for reporting     CVE-2011-1745, CVE-2011-2022, CVE-2011-1746, and CVE-2011-2484; the Ubuntu     Security Team for reporting CVE-2011-1833; Robert Swiecki for reporting     CVE-2011-2496; Li Yu for reporting CVE-2011-2521; Brent Meshier for     reporting CVE-2011-2723; and Peter Huewe for reporting CVE-2011-1160. The     Ubuntu Security Team acknowledges Vasiliy Kulikov of Openwall and Dan     Rosenberg as the original reporters of CVE-2011-1833.

    This update also fixes various bugs and adds one enhancement. Documentation     for these changes will be available shortly from the Technical Notes     document linked to in the References section.

    Users should upgrade to these updated packages, which contain backported     patches to correct these issues, and fix the bugs and add the enhancement     noted in the Technical Notes. The system must be rebooted for this update     to take effect.

Tenable has extracted the preceding description block directly from the Red Hat Enterprise Linux security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

Ryan Sweat discovered that the kernel incorrectly handled certain VLAN packets. On some systems, a remote attacker could send specially crafted traffic to crash the system, leading to a denial of service.
(CVE-2011-1576)

Timo Warns discovered that the EFI GUID partition table was not correctly parsed. A physically local attacker that could insert mountable devices could exploit this to crash the system or possibly gain root privileges. (CVE-2011-1776)

Dan Rosenberg discovered that the IPv4 diagnostic routines did not correctly validate certain requests. A local attacker could exploit this to consume CPU resources, leading to a denial of service.
(CVE-2011-2213)

Dan Rosenberg discovered that the Bluetooth stack incorrectly handled certain L2CAP requests. If a system was using Bluetooth, a remote attacker could send specially crafted traffic to crash the system or gain root privileges. (CVE-2011-2497)

Mauro Carvalho Chehab discovered that the si4713 radio driver did not correctly check the length of memory copies. If this hardware was available, a local attacker could exploit this to crash the system or gain root privileges. (CVE-2011-2700)

Herbert Xu discovered that certain fields were incorrectly handled when Generic Receive Offload (CVE-2011-2723)

Time Warns discovered that long symlinks were incorrectly handled on Be filesystems. A local attacker could exploit this with a malformed Be filesystem and crash the system, leading to a denial of service.
(CVE-2011-2928)

Dan Kaminsky discovered that the kernel incorrectly handled random sequence number generation. An attacker could use this flaw to possibly predict sequence numbers and inject packets. (CVE-2011-3188)

Darren Lavender discovered that the CIFS client incorrectly handled certain large values. A remote attacker with a malicious server could exploit this to crash the system or possibly execute arbitrary code as the root user. (CVE-2011-3191)

Dan Rosenberg discovered that multiple terminal ioctls did not correctly initialize structure memory. A local attacker could exploit this to read portions of kernel stack memory, leading to a loss of privacy. (CVE-2010-4076, CVE-2010-4077)

Alex Shi and Eric Dumazet discovered that the network stack did not correctly handle packet backlogs. A remote attacker could exploit this by sending a large amount of network traffic to cause the system to run out of memory, leading to a denial of service. (CVE-2010-4251, CVE-2010-4805)

It was discovered that the /proc filesystem did not correctly handle permission changes when programs executed. A local attacker could hold open files to examine details about programs running with higher privileges, potentially increasing the chances of exploiting additional vulnerabilities. (CVE-2011-1020)

Dan Rosenberg discovered that the X.25 Rose network stack did not correctly handle certain fields. If a system was running with Rose enabled, a remote attacker could send specially crafted traffic to gain root privileges. (CVE-2011-1493)

Timo Warns discovered that the GUID partition parsing routines did not correctly validate certain structures. A local attacker with physical access could plug in a specially crafted block device to crash the system, leading to a denial of service. (CVE-2011-1577)

It was discovered that CIFS incorrectly handled authentication. When a user had a CIFS share mounted that required authentication, a local user could mount the same share without knowing the correct password.
(CVE-2011-1585)

It was discovered that the GRE protocol incorrectly handled netns initialization. A remote attacker could send a packet while the ip_gre module was loading, and crash the system, leading to a denial of service. (CVE-2011-1767)

It was discovered that the IP/IP protocol incorrectly handled netns initialization. A remote attacker could send a packet while the ipip module was loading, and crash the system, leading to a denial of service. (CVE-2011-1768)

Ben Hutchings reported a flaw in the kernel's handling of corrupt LDM partitions. A local user could exploit this to cause a denial of service or escalate privileges. (CVE-2011-2182)

Andrea Righi discovered a race condition in the KSM memory merging support. If KSM was being used, a local attacker could exploit this to crash the system, leading to a denial of service. (CVE-2011-2183)

Dan Rosenberg discovered that the IPv4 diagnostic routines did not correctly validate certain requests. A local attacker could exploit this to consume CPU resources, leading to a denial of service.
(CVE-2011-2213)

Vasiliy Kulikov discovered that taskstats listeners were not correctly handled. A local attacker could exploit this to exhaust memory and CPU resources, leading to a denial of service. (CVE-2011-2484)

It was discovered that Bluetooth l2cap and rfcomm did not correctly initialize structures. A local attacker could exploit this to read portions of the kernel stack, leading to a loss of privacy.
(CVE-2011-2492)

Mauro Carvalho Chehab discovered that the si4713 radio driver did not correctly check the length of memory copies. If this hardware was available, a local attacker could exploit this to crash the system or gain root privileges. (CVE-2011-2700)

Herbert Xu discovered that certain fields were incorrectly handled when Generic Receive Offload (CVE-2011-2723)

Vasiliy Kulikov discovered that the Comedi driver did not correctly clear memory. A local attacker could exploit this to read kernel stack memory, leading to a loss of privacy. (CVE-2011-2909)

The performance counter subsystem did not correctly handle certain counters. A local attacker could exploit this to crash the system, leading to a denial of service. (CVE-2011-2918)

A flaw was found in the Linux kernel's /proc/*/*map* interface. A local, unprivileged user could exploit this flaw to cause a denial of service. (CVE-2011-3637)

Ben Hutchings discovered several flaws in the Linux Rose (X.25 PLP) layer. A local user or a remote user on an X.25 network could exploit these flaws to execute arbitrary code as root. (CVE-2011-4914).

Note that Tenable Network Security has extracted the preceding description block directly from the Ubuntu security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

Dan Rosenberg discovered that multiple terminal ioctls did not correctly initialize structure memory. A local attacker could exploit this to read portions of kernel stack memory, leading to a loss of privacy. (CVE-2010-4076, CVE-2010-4077)

Alex Shi and Eric Dumazet discovered that the network stack did not correctly handle packet backlogs. A remote attacker could exploit this by sending a large amount of network traffic to cause the system to run out of memory, leading to a denial of service. (CVE-2010-4251, CVE-2010-4805)

It was discovered that the /proc filesystem did not correctly handle permission changes when programs executed. A local attacker could hold open files to examine details about programs running with higher privileges, potentially increasing the chances of exploiting additional vulnerabilities. (CVE-2011-1020)

Dan Rosenberg discovered that the X.25 Rose network stack did not correctly handle certain fields. If a system was running with Rose enabled, a remote attacker could send specially crafted traffic to gain root privileges. (CVE-2011-1493)

Timo Warns discovered that the GUID partition parsing routines did not correctly validate certain structures. A local attacker with physical access could plug in a specially crafted block device to crash the system, leading to a denial of service. (CVE-2011-1577)

It was discovered that CIFS incorrectly handled authentication. When a user had a CIFS share mounted that required authentication, a local user could mount the same share without knowing the correct password.
(CVE-2011-1585)

It was discovered that the GRE protocol incorrectly handled netns initialization. A remote attacker could send a packet while the ip_gre module was loading, and crash the system, leading to a denial of service. (CVE-2011-1767)

It was discovered that the IP/IP protocol incorrectly handled netns initialization. A remote attacker could send a packet while the ipip module was loading, and crash the system, leading to a denial of service. (CVE-2011-1768)

Ben Hutchings reported a flaw in the kernel's handling of corrupt LDM partitions. A local user could exploit this to cause a denial of service or escalate privileges. (CVE-2011-2182)

Andrea Righi discovered a race condition in the KSM memory merging support. If KSM was being used, a local attacker could exploit this to crash the system, leading to a denial of service. (CVE-2011-2183)

Dan Rosenberg discovered that the IPv4 diagnostic routines did not correctly validate certain requests. A local attacker could exploit this to consume CPU resources, leading to a denial of service.
(CVE-2011-2213)

Vasiliy Kulikov discovered that taskstats listeners were not correctly handled. A local attacker could expoit this to exhaust memory and CPU resources, leading to a denial of service. (CVE-2011-2484)

It was discovered that Bluetooth l2cap and rfcomm did not correctly initialize structures. A local attacker could exploit this to read portions of the kernel stack, leading to a loss of privacy.
(CVE-2011-2492)

Mauro Carvalho Chehab discovered that the si4713 radio driver did not correctly check the length of memory copies. If this hardware was available, a local attacker could exploit this to crash the system or gain root privileges. (CVE-2011-2700)

Herbert Xu discovered that certain fields were incorrectly handled when Generic Receive Offload (CVE-2011-2723)

Vasiliy Kulikov discovered that the Comedi driver did not correctly clear memory. A local attacker could exploit this to read kernel stack memory, leading to a loss of privacy. (CVE-2011-2909)

The performance counter subsystem did not correctly handle certain counters. A local attacker could exploit this to crash the system, leading to a denial of service. (CVE-2011-2918)

A flaw was found in the Linux kernel's /proc/*/*map* interface. A local, unprivileged user could exploit this flaw to cause a denial of service. (CVE-2011-3637)

Ben Hutchings discovered several flaws in the Linux Rose (X.25 PLP) layer. A local user or a remote user on an X.25 network could exploit these flaws to execute arbitrary code as root. (CVE-2011-4914).

Several vulnerabilities have been discovered in the Linux kernel that may lead to a denial of service or privilege escalation. The Common Vulnerabilities and Exposures project identifies the following problems :

  - CVE-2011-1020     Kees Cook discovered an issue in the /proc filesystem     that allows local users to gain access to sensitive     process information after execution of a setuid binary.

  - CVE-2011-1576     Ryan Sweat discovered an issue in the VLAN     implementation. Local users may be able to cause a     kernel memory leak, resulting in a denial of service.

  - CVE-2011-2484     Vasiliy Kulikov of Openwall discovered that the number     of exit handlers that a process can register is not     capped, resulting in local denial of service through     resource exhaustion (CPU time and memory).

  - CVE-2011-2491     Vasily Averin discovered an issue with the NFS locking     implementation. A malicious NFS server can cause a     client to hang indefinitely in an unlock call.

  - CVE-2011-2492     Marek Kroemeke and Filip Palian discovered that     uninitialized struct elements in the Bluetooth subsystem     could lead to a leak of sensitive kernel memory through     leaked stack memory.

  - CVE-2011-2495     Vasiliy Kulikov of Openwall discovered that the io file     of a process' proc directory was world-readable,     resulting in local information disclosure of information     such as password lengths.

  - CVE-2011-2496     Robert Swiecki discovered that mremap() could be abused     for local denial of service by triggering a BUG_ON     assert.

  - CVE-2011-2497     Dan Rosenberg discovered an integer underflow in the     Bluetooth subsystem, which could lead to denial of     service or privilege escalation.

  - CVE-2011-2517     It was discovered that the netlink-based wireless     configuration interface performed insufficient length     validation when parsing SSIDs, resulting in buffer     overflows. Local users with the CAP_NET_ADMIN capability     can cause a denial of service.

  - CVE-2011-2525     Ben Pfaff reported an issue in the network scheduling     code. A local user could cause a denial of service (NULL     pointer dereference) by sending a specially crafted     netlink message.

  - CVE-2011-2700     Mauro Carvalho Chehab of Red Hat reported a buffer     overflow issue in the driver for the Si4713 FM Radio     Transmitter driver used by N900 devices. Local users     could exploit this issue to cause a denial of service or     potentially gain elevated privileges.

  - CVE-2011-2723     Brent Meshier reported an issue in the GRO (generic     receive offload) implementation. This can be exploited     by remote users to create a denial of service (system     crash) in certain network device configurations.

  - CVE-2011-2905     Christian Ohm discovered that the 'perf' analysis tool     searches for its config files in the current working     directory. This could lead to denial of service or     potential privilege escalation if a user with elevated     privileges is tricked into running 'perf' in a directory     under the control of the attacker.

  - CVE-2011-2909     Vasiliy Kulikov of Openwall discovered that a     programming error in the Comedi driver could lead to the     information disclosure through leaked stack memory.

  - CVE-2011-2918     Vince Weaver discovered that incorrect handling of     software event overflows in the 'perf' analysis tool     could lead to local denial of service.

  - CVE-2011-2928     Timo Warns discovered that insufficient validation of Be     filesystem images could lead to local denial of service     if a malformed filesystem image is mounted.

  - CVE-2011-3188     Dan Kaminsky reported a weakness of the sequence number     generation in the TCP protocol implementation. This can     be used by remote attackers to inject packets into an     active session.

  - CVE-2011-3191     Darren Lavender reported an issue in the Common Internet     File System (CIFS). A malicious file server could cause     memory corruption leading to a denial of service.

This update also includes a fix for a regression introduced with the previous security fix for CVE-2011-1768 (Debian bug #633738).

The remote CentOS system is missing a security update which has been documented in Red Hat advisory RHSA-2011-1386.

ID	Name	Product	Family	Severity
79280	RHEL 5 : rhev-hypervisor (RHSA-2011:1408)	Nessus	Red Hat Local Security Checks	medium
76635	RHEL 6 : MRG (RHSA-2012:0010)	Nessus	Red Hat Local Security Checks	critical
75882	openSUSE Security Update : kernel (openSUSE-SU-2012:0236-1)	Nessus	SuSE Local Security Checks	high
75557	openSUSE Security Update : kernel (openSUSE-SU-2012:0206-1)	Nessus	SuSE Local Security Checks	high
69575	Amazon Linux AMI : kernel (ALAS-2011-16)	Nessus	Amazon Linux Local Security Checks	critical
68422	Oracle Linux 5 / 6 : Unbreakable Enterprise kernel (ELSA-2011-2029)	Nessus	Oracle Linux Local Security Checks	medium
68375	Oracle Linux 5 : kernel (ELSA-2011-1386)	Nessus	Oracle Linux Local Security Checks	critical
68364	Oracle Linux 6 : kernel (ELSA-2011-1350)	Nessus	Oracle Linux Local Security Checks	medium
64003	RHEL 5 : kernel (RHSA-2011:1321)	Nessus	Red Hat Local Security Checks	high
61162	Scientific Linux Security Update : kernel on SL5.x i386/x86_64	Nessus	Scientific Linux Local Security Checks	critical
61148	Scientific Linux Security Update : kernel on SL6.x i386/x86_64	Nessus	Scientific Linux Local Security Checks	medium
56768	Ubuntu 10.04 LTS : linux-lts-backport-natty vulnerabilities (USN-1256-1)	Nessus	Ubuntu Local Security Checks	critical
56645	Ubuntu 11.04 : linux vulnerabilities (USN-1246-1)	Nessus	Ubuntu Local Security Checks	critical
56640	USN-1241-1 : linux-fsl-imx51 vulnerabilities	Nessus	Ubuntu Local Security Checks	critical
56577	RHEL 5 : kernel (RHSA-2011:1386)	Nessus	Red Hat Local Security Checks	critical
56569	CentOS 5 : kernel (CESA-2011:1386)	Nessus	CentOS Local Security Checks	critical
56479	USN-1228-1 : linux-ti-omap4 vulnerabilities	Nessus	Ubuntu Local Security Checks	critical
56466	Ubuntu 10.10 : linux vulnerabilities (USN-1227-1)	Nessus	Ubuntu Local Security Checks	critical
56404	RHEL 6 : kernel (RHSA-2011:1350)	Nessus	Red Hat Local Security Checks	medium
56345	USN-1220-1 : linux-ti-omap4 vulnerabilities	Nessus	Ubuntu Local Security Checks	critical
56344	Ubuntu 10.04 LTS : linux-lts-backport-maverick vulnerabilities (USN-1219-1)	Nessus	Ubuntu Local Security Checks	critical
56343	Ubuntu 10.04 LTS : linux vulnerabilities (USN-1218-1)	Nessus	Ubuntu Local Security Checks	high
56305	Ubuntu 10.04 LTS : linux-ec2 vulnerabilities (USN-1216-1)	Nessus	Ubuntu Local Security Checks	high
56207	Ubuntu 10.10 : linux-mvl-dove vulnerabilities (USN-1208-1)	Nessus	Ubuntu Local Security Checks	high
56191	Ubuntu 10.04 LTS : linux-mvl-dove vulnerabilities (USN-1203-1)	Nessus	Ubuntu Local Security Checks	high
56130	Debian DSA-2303-2 : linux-2.6 - privilege escalation/denial of service/information leak	Nessus	Debian Local Security Checks	critical
801510	CentOS RHSA-2011-1386 Security Check	Log Correlation Engine	Generic	high

Detections

Analytics

CVE-2011-2723

high

Tenable Plugins

medium

critical

high

high

critical

medium

critical

medium

high

critical

medium

critical

critical

critical

critical

critical

critical

critical

medium

critical

critical

high

high

high

high

critical

high