Linux SCTP (lksctp) before 2.6.17 allows remote attackers to cause a denial of service (infinite recursion and crash) via a packet that contains two or more DATA fragments, which causes an skb pointer to refer back to itself when the full message is reassembled, leading to infinite recursion in the sctp_skb_pull function.

An integer overflow was discovered in the do_replace() function. A local user process with the CAP_NET_ADMIN capability could exploit this to execute arbitrary commands with full root privileges. However, none of Ubuntu's supported packages use this capability with any non-root user, so this only affects you if you use some third party software like the OpenVZ virtualization system. (CVE-2006-0038)

On EMT64 CPUs, the kernel did not properly handle uncanonical return addresses. A local user could exploit this to trigger a kernel crash.
(CVE-2006-0744)

Al Viro discovered a local Denial of Service in the sysfs write buffer handling. By writing a block with a length exactly equal to the processor's page size to any writable file in /sys, a local attacker could cause a kernel crash. (CVE-2006-1055)

Jan Beulich discovered an information leak in the handling of registers for the numeric coprocessor when running on AMD processors.
This allowed processes to see the coprocessor execution state of other processes, which could reveal sensitive data in the case of cryptographic computations. (CVE-2006-1056)

Marcel Holtmann discovered that the sys_add_key() did not check that a new user key is added to a proper keyring. By attempting to add a key to a normal user key (which is not a keyring), a local attacker could exploit this to crash the kernel. (CVE-2006-1522)

Ingo Molnar discovered that the SCTP protocol connection tracking module in netfilter got stuck in an infinite loop on certain empty packet chunks. A remote attacker could exploit this to cause the computer to hang. (CVE-2006-1527)

The SCSI I/O driver did not correctly handle the VM_IO flag for memory mapped pages used for data transfer. A local user could exploit this to cause a kernel crash. (CVE-2006-1528)

The choose_new_parent() contained obsolete debugging code. A local user could exploit this to cause a kernel crash. (CVE-2006-1855)

Kostik Belousov discovered that the readv() and writev() functions did not query LSM modules for access permission. This could be exploited to circumvent access restrictions defined by LSM modules such as SELinux or AppArmor. (CVE-2006-1856)

The SCTP driver did not properly verify certain parameters when receiving a HB-ACK chunk. By sending a specially crafted packet to an SCTP socket, a remote attacker could exploit this to trigger a buffer overflow, which could lead to a crash or possibly even arbitrary code execution. (CVE-2006-1857)

The sctp_walk_params() function in the SCTP driver incorrectly used rounded values for bounds checking instead of the precise values. By sending a specially crafted packet to an SCTP socket, a remote attacker could exploit this to crash the kernel. (CVE-2006-1858)

Bjoern Steinbrink reported a memory leak in the __setlease() function.
A local attacker could exploit this to exhaust kernel memory and render the computer unusable (Denial of Service). (CVE-2006-1859)

Daniel Hokka Zakrisson discovered that the lease_init() did not properly handle locking. A local attacker could exploit this to cause a kernel deadlock (Denial of Service). (CVE-2006-1860)

Mark Moseley discovered that the CIFS file system driver did not filter out '..\\' path components. A local attacker could exploit this to break out of a chroot environment on a mounted SMB share.
(CVE-2006-1863) The same vulnerability applies to the older smb file system. (CVE-2006-1864)

Hugh Dickins discovered that the mprotect() function allowed an user to change a read-only shared memory attachment to become writable, which bypasses IPC (inter-process communication) permissions.
(CVE-2006-2071)

The SCTP (Stream Control Transmission Protocol) driver triggered a kernel panic on unexpected packets while the session was in the CLOSED state, instead of silently ignoring the packets. A remote attacker could exploit this to crash the computer. (CVE-2006-2271)

The SCTP driver did not handle control chunks if they arrived in fragmented packets. By sending specially crafted packets to an SCTP socket, a remote attacker could exploit this to crash the target machine. (CVE-2006-2272)

The SCTP driver did not correctly handle packets containing more than one DATA fragment. By sending specially crafted packets to an SCTP socket, a remote attacker could exploit this to crash the target machine. (CVE-2006-2274)

The SCTP driver did not correcly buffer incoming packets. By sending a large number of small messages to a receiver application that cannot process the messages quickly enough, a remote attacker could exploit this to cause a deadlock in the target machine (Denial of Service).
(CVE-2006-2275)

Patrick McHardy discovered that the snmp_trap_decode() function did not correctly handle memory allocation in some error conditions. By sending specially crafted packets to a machine which uses the SNMP network address translation (NAT), a remote attacker could exploit this to crash that machine. (CVE-2006-2444)

In addition, the Ubuntu 6.06 LTS update fixes a range of bugs.

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.

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

  - CVE-2005-3359     Franz Filz discovered that some socket calls permit     causing inconsistent reference counts on loadable     modules, which allows local users to cause a denial of     service.

  - CVE-2006-0038     'Solar Designer' discovered that arithmetic computations     in netfilter's do_replace() function can lead to a     buffer overflow and the execution of arbitrary code.
    However, the operation requires CAP_NET_ADMIN     privileges, which is only an issue in virtualization     systems or fine grained access control systems.

  - CVE-2006-0039     'Solar Designer' discovered a race condition in     netfilter's do_add_counters() function, which allows     information disclosure of kernel memory by exploiting a     race condition. Likewise, it requires CAP_NET_ADMIN     privileges. 

  - CVE-2006-0456     David Howells discovered that the s390 assembly version     of the strnlen_user() function incorrectly returns some     string size values.

  - CVE-2006-0554     It was discovered that the ftruncate() function of XFS     can expose unallocated blocks, which allows information     disclosure of previously deleted files.

  - CVE-2006-0555     It was discovered that some NFS file operations on     handles mounted with O_DIRECT can force the kernel into     a crash.

  - CVE-2006-0557     It was discovered that the code to configure memory     policies allows tricking the kernel into a crash, thus     allowing denial of service.

  - CVE-2006-0558     It was discovered by Cliff Wickman that perfmon for the     IA64 architecture allows users to trigger a BUG()     assert, which allows denial of service.

  - CVE-2006-0741     Intel EM64T systems were discovered to be susceptible to     a local DoS due to an endless recursive fault related to     a bad ELF entry address.

  - CVE-2006-0742     Alan and Gareth discovered that the ia64 platform had an     incorrectly declared die_if_kernel() function as 'does     never return' which could be exploited by a local     attacker resulting in a kernel crash.

  - CVE-2006-0744     The Linux kernel did not properly handle uncanonical     return addresses on Intel EM64T CPUs, reporting     exceptions in the SYSRET instead of the next     instruction, causing the kernel exception handler to run     on the user stack with the wrong GS. This may result in     a DoS due to a local user changing the frames.

  - CVE-2006-1056     AMD64 machines (and other 7th and 8th generation     AuthenticAMD processors) were found to be vulnerable to     sensitive information leakage, due to how they handle     saving and restoring the FOP, FIP, and FDP x87 registers     in FXSAVE/FXRSTOR when an exception is pending. This     allows a process to determine portions of the state of     floating point instructions of other processes.

  - CVE-2006-1242     Marco Ivaldi discovered that there was an unintended     information disclosure allowing remote attackers to     bypass protections against Idle Scans (nmap -sI) by     abusing the ID field of IP packets and bypassing the     zero IP ID in DF packet countermeasure. This was a     result of the ip_push_pending_frames function improperly     incremented the IP ID field when sending a RST after     receiving unsolicited TCP SYN-ACK packets.

  - CVE-2006-1368     Shaun Tancheff discovered a buffer overflow (boundary     condition error) in the USB Gadget RNDIS implementation     allowing remote attackers to cause a DoS. While creating     a reply message, the driver allocated memory for the     reply data, but not for the reply structure. The kernel     fails to properly bounds-check user-supplied data before     copying it to an insufficiently sized memory buffer.
    Attackers could crash the system, or possibly execute     arbitrary machine code.

  - CVE-2006-1523     Oleg Nesterov reported an unsafe BUG_ON call in signal.c     which was introduced by RCU signal handling. The BUG_ON     code is protected by siglock while the code in     switch_exit_pids() uses tasklist_lock. It may be     possible for local users to exploit this to initiate a     denial of service attack (DoS).

  - CVE-2006-1524     Hugh Dickins discovered an issue in the madvise_remove()     function wherein file and mmap restrictions are not     followed, allowing local users to bypass IPC permissions     and replace portions of readonly tmpfs files with     zeroes.

  - CVE-2006-1525     Alexandra Kossovsky reported a NULL pointer dereference     condition in ip_route_input() that can be triggered by a     local user by requesting a route for a multicast IP     address, resulting in a denial of service (panic).

  - CVE-2006-1857     Vlad Yasevich reported a data validation issue in the     SCTP subsystem that may allow a remote user to overflow     a buffer using a badly formatted HB-ACK chunk, resulting     in a denial of service.

  - CVE-2006-1858     Vlad Yasevich reported a bug in the bounds checking code     in the SCTP subsystem that may allow a remote attacker     to trigger a denial of service attack when rounded     parameter lengths are used to calculate parameter     lengths instead of the actual values.

  - CVE-2006-1863     Mark Mosely discovered that chroots residing on an CIFS     share can be escaped with specially crafted 'cd'     sequences.

  - CVE-2006-1864     Mark Mosely discovered that chroots residing on an SMB     share can be escaped with specially crafted 'cd'     sequences.

  - CVE-2006-2271     The 'Mu security team' discovered that carefully crafted     ECNE chunks can cause a kernel crash by accessing     incorrect state stable entries in the SCTP networking     subsystem, which allows denial of service.

  - CVE-2006-2272     The 'Mu security team' discovered that fragmented SCTP     control chunks can trigger kernel panics, which allows     for denial of service attacks.

  - CVE-2006-2274     It was discovered that SCTP packets with two initial     bundled data packets can lead to infinite recursion,     which allows for denial of service attacks.

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

  - CVE-2006-0038     'Solar Designer' discovered that arithmetic computations     in netfilter's do_replace() function can lead to a     buffer overflow and the execution of arbitrary code.
    However, the operation requires CAP_NET_ADMIN     privileges, which is only an issue in virtualization     systems or fine grained access control systems.

  - CVE-2006-0039     'Solar Designer' discovered a race condition in     netfilter's do_add_counters() function, which allows     information disclosure of kernel memory by exploiting a     race condition. Like CVE-2006-0038, it requires     CAP_NET_ADMIN privileges.

  - CVE-2006-0741     Intel EM64T systems were discovered to be susceptible to     a local DoS due to an endless recursive fault related to     a bad ELF entry address.

  - CVE-2006-0742     Incorrectly declared die_if_kernel() function as 'does     never return' which could be exploited by a local     attacker resulting in a kernel crash.

  - CVE-2006-1056     AMD64 machines (and other 7th and 8th generation     AuthenticAMD processors) were found to be vulnerable to     sensitive information leakage, due to how they handle     saving and restoring the FOP, FIP, and FDP x87 registers     in FXSAVE/FXRSTOR when an exception is pending. This     allows a process to determine portions of the state of     floating point instructions of other processes.

  - CVE-2006-1242     Marco Ivaldi discovered that there was an unintended     information disclosure allowing remote attackers to     bypass protections against Idle Scans (nmap -sI) by     abusing the ID field of IP packets and bypassing the     zero IP ID in DF packet countermeasure. This was a     result of the ip_push_pending_frames function improperly     incremented the IP ID field when sending a RST after     receiving unsolicited TCP SYN-ACK packets.

  - CVE-2006-1343     Pavel Kankovsky reported the existence of a potential     information leak resulting from the failure to     initialize sin.sin_zero in the IPv4 socket code.

  - CVE-2006-1368     Shaun Tancheff discovered a buffer overflow (boundary     condition error) in the USB Gadget RNDIS implementation     allowing remote attackers to cause a DoS. While creating     a reply message, the driver allocated memory for the     reply data, but not for the reply structure. The kernel     fails to properly bounds-check user-supplied data before     copying it to an insufficiently sized memory buffer.
    Attackers could crash the system, or possibly execute     arbitrary machine code.

  - CVE-2006-1524     Hugh Dickins discovered an issue in the madvise_remove()     function wherein file and mmap restrictions are not     followed, allowing local users to bypass IPC permissions     and replace portions of readonly tmpfs files with     zeroes.

  - CVE-2006-1525     Alexandra Kossovsky reported a NULL pointer dereference     condition in ip_route_input() that can be triggered by a     local user by requesting a route for a multicast IP     address, resulting in a denial of service (panic).

  - CVE-2006-1857     Vlad Yasevich reported a data validation issue in the     SCTP subsystem that may allow a remote user to overflow     a buffer using a badly formatted HB-ACK chunk, resulting     in a denial of service.

  - CVE-2006-1858     Vlad Yasevich reported a bug in the bounds checking code     in the SCTP subsystem that may allow a remote attacker     to trigger a denial of service attack when rounded     parameter lengths are used to calculate parameter     lengths instead of the actual values.

  - CVE-2006-1864     Mark Mosely discovered that chroots residing on an SMB     share can be escaped with specially crafted 'cd'     sequences.

  - CVE-2006-2271     The 'Mu security team' discovered that carefully crafted     ECNE chunks can cause a kernel crash by accessing     incorrect state stable entries in the SCTP networking     subsystem, which allows denial of service.

  - CVE-2006-2272     The 'Mu security team' discovered that fragmented SCTP     control chunks can trigger kernel panics, which allows     for denial of service attacks.

  - CVE-2006-2274     It was discovered that SCTP packets with two initial     bundled data packets can lead to infinite recursion,     which allows for denial of service attacks.

A number of vulnerabilities were discovered and corrected in the Linux 2.6 kernel :

The kernel did not clear sockaddr_in.sin_zero before returning IPv4 socket names for the getsockopt function, which could allow a local user to obtain portions of potentially sensitive memory if getsockopt() is called with SO_ORIGINAL_DST (CVE-2006-1343).

Prior to 2.6.16, a buffer overflow in the USB Gadget RNDIS implementation could allow a remote attacker to cause a Denial of Service via a remote NDIS response (CVE-2006-1368).

Prior to 2.6.13, local users could cause a Denial of Service (crash) via a dio transfer from the sg driver to memory mapped IO space (CVE-2006-1528).

Prior to and including 2.6.16, the kernel did not add the appropriate LSM file_permission hooks to the readv and writev functions, which could allow an attacker to bypass intended access restrictions (CVE-2006-1856).

Prior to 2.6.16.17, a buffer oveflow in SCTP could allow a remote attacker to cause a DoS (crash) and possibly execute arbitrary code via a malformed HB-ACK chunk (CVE-2006-1857).

Prior to 2.6.16.17, SCTP could allow a remote attacker to cause a DoS (crash) and possibly execute arbitrary code via a chunk length that is inconsistent with the actual length of provided parameters (CVE-2006-1858).

Prior to 2.6.16.16, a memory leak in fs/locks.c could allow an attacker to cause a DoS (memory consumption) via unspecified actions (CVE-2006-1859).

Prior to 2.6.16.16, lease_init in fs/locks.c could allow an attacker to cause a DoS (fcntl_setlease lockup) via certain actions (CVE-2006-1860).

Prior to 2.6.17, SCTP allowed remote attackers to cause a DoS (infinite recursion and crash) via a packet that contains two or more DATA fragments (CVE-2006-2274).

Prior to 2.6.16.21, a race condition in run_posix_cpu timers could allow a local user to cause a DoS (BUG_ON crash) by causing one CPU to attach a timer to a process that is exiting (CVE-2006-2445).

Prior to 2.6.17.1, xt_sctp in netfilter could allow an attacker to cause a DoS (infinite loop) via an SCTP chunk with a 0 length (CVE-2006-3085).

As well, an issue where IPC could hit an unmapped vmalloc page when near the page boundary has been corrected.

In addition to these security fixes, other fixes have been included such as :

  - avoid automatic update of kernel-source without updating     the kernel

    - fix USB EHCI handoff code, which made some machines       hang while booting

  - disable USB_BANDWIDTH which corrects a known problem in     some USB sound devices

  - fix a bluetooth refcounting bug which could hang the     machine

    - fix a NULL pointer dereference in USB-Serial's       serial_open() function

  - add missing wakeup in pl2303 TIOCMIWAIT handling

    - fix a possible user-after-free in USB-Serial core

    - suspend/resume fixes

    - HPET timer fixes

    - prevent fixed button event to reach userspace on S3       resume

    - add sysfs support in ide-tape

    - fix ASUS P5S800 reboot

Finally, a new drbd-utils package is provided that is a required upgrade with this new kernel due to a logic bug in the previously shipped version of drbd-utils that could cause a kernel panic on the master when a slave went offline.

The provided packages are patched to fix these vulnerabilities. All users are encouraged to upgrade to these updated kernels.

To update your kernel, please follow the directions located at :

http://www.mandriva.com/en/security/kernelupdate

Updated kernel packages that fix several security issues in the Red Hat Enterprise Linux 4 kernel are now available.

This security advisory has been rated as having important security impact by the Red Hat Security Response Team.

The Linux kernel handles the basic functions of the operating system.

These new kernel packages contain fixes for the security issues described below :

* a flaw in the IPv6 implementation that allowed a local user to cause a denial of service (infinite loop and crash) (CVE-2005-2973, important)

* a flaw in the bridge implementation that allowed a remote user to cause forwarding of spoofed packets via poisoning of the forwarding table with already dropped frames (CVE-2005-3272, moderate)

* a flaw in the atm module that allowed a local user to cause a denial of service (panic) via certain socket calls (CVE-2005-3359, important)

* a flaw in the NFS client implementation that allowed a local user to cause a denial of service (panic) via O_DIRECT writes (CVE-2006-0555, important)

* a difference in 'sysretq' operation of EM64T (as opposed to Opteron) processors that allowed a local user to cause a denial of service (crash) upon return from certain system calls (CVE-2006-0741 and CVE-2006-0744, important)

* a flaw in the keyring implementation that allowed a local user to cause a denial of service (OOPS) (CVE-2006-1522, important)

* a flaw in IP routing implementation that allowed a local user to cause a denial of service (panic) via a request for a route for a multicast IP (CVE-2006-1525, important)

* a flaw in the SCTP-netfilter implementation that allowed a remote user to cause a denial of service (infinite loop) (CVE-2006-1527, important)

* a flaw in the sg driver that allowed a local user to cause a denial of service (crash) via a dio transfer to memory mapped (mmap) IO space (CVE-2006-1528, important)

* a flaw in the threading implementation that allowed a local user to cause a denial of service (panic) (CVE-2006-1855, important)

* two missing LSM hooks that allowed a local user to bypass the LSM by using readv() or writev() (CVE-2006-1856, moderate)

* a flaw in the virtual memory implementation that allowed local user to cause a denial of service (panic) by using the lsof command (CVE-2006-1862, important)

* a directory traversal vulnerability in smbfs that allowed a local user to escape chroot restrictions for an SMB-mounted filesystem via '..\\' sequences (CVE-2006-1864, moderate)

* a flaw in the ECNE chunk handling of SCTP that allowed a remote user to cause a denial of service (panic) (CVE-2006-2271, moderate)

* a flaw in the handling of COOKIE_ECHO and HEARTBEAT control chunks of SCTP that allowed a remote user to cause a denial of service (panic) (CVE-2006-2272, moderate)

* a flaw in the handling of DATA fragments of SCTP that allowed a remote user to cause a denial of service (infinite recursion and crash) (CVE-2006-2274, moderate)

All Red Hat Enterprise Linux 4 users are advised to upgrade their kernels to the packages associated with their machine architectures and configurations as listed in this erratum.

The remote CentOS system is missing a security update which has been documented in Red Hat advisory RHSA-2006-0493.

ID	Name	Product	Family	Severity
27877	Ubuntu 5.04 / 5.10 / 6.06 LTS : linux-source-2.6.10/2.6.12/2.6.15 vulnerabilities (USN-302-1)	Nessus	Ubuntu Local Security Checks	high
22645	Debian DSA-1103-1 : kernel-source-2.6.8 - several vulnerabilities	Nessus	Debian Local Security Checks	critical
22639	Debian DSA-1097-1 : kernel-source-2.4.27 - several vulnerabilities	Nessus	Debian Local Security Checks	critical
22058	Mandrake Linux Security Advisory : kernel (MDKSA-2006:123)	Nessus	Mandriva Local Security Checks	critical
21997	CentOS 4 : kernel (CESA-2006:0493)	Nessus	CentOS Local Security Checks	high
21592	RHEL 4 : kernel (RHSA-2006:0493)	Nessus	Red Hat Local Security Checks	high
801418	CentOS RHSA-2006-0493 Security Check	Log Correlation Engine	Generic	high

Detections

Analytics

CVE-2006-2274

high

Tenable Plugins

high

critical

critical

critical

high

high

high