smbfs in Linux kernel 2.6.8 and other versions, and 2.4.x before 2.4.34, when UNIX extensions are enabled, ignores certain mount options, which could cause clients to use server-specified uid, gid and mode settings.

Mark Dowd discovered that the netfilter iptables module did not correcly handle fragmented packets. By sending specially crafted packets, a remote attacker could exploit this to bypass firewall rules. This has only be fixed for Ubuntu 6.10; the corresponding fix for Ubuntu 5.10 and 6.06 will follow soon. (CVE-2006-4572)

Dmitriy Monakhov discovered an information leak in the
__block_prepare_write() function. During error recovery, this function did not properly clear memory buffers which could allow local users to read portions of unlinked files. This only affects Ubuntu 5.10.
(CVE-2006-4813)

ADLab Venustech Info Ltd discovered that the ATM network driver referenced an already released pointer in some circumstances. By sending specially crafted packets to a host over ATM, a remote attacker could exploit this to crash that host. This does not affect Ubuntu 6.10. (CVE-2006-4997)

Matthias Andree discovered that the NFS locking management daemon (lockd) did not correctly handle mixing of 'lock' and 'nolock' option mounts on the same client. A remote attacker could exploit this to crash lockd and thus rendering the NFS imports inaccessible. This only affects Ubuntu 5.10. (CVE-2006-5158)

The task switching code did not save and restore EFLAGS of processes.
By starting a specially crafted executable, a local attacker could exploit this to eventually crash many other running processes. This does not affect Ubuntu 6.10. (CVE-2006-5173)

James Morris discovered that the ip6fl_get_n() function incorrectly handled flow labels. A local attacker could exploit this to crash the kernel. (CVE-2006-5619)

Fabio Massimo Di Nitto discovered that the sys_get_robust_list and sys_set_robust_list system calls lacked proper lock handling on the powerpc platform. A local attacker could exploit this to create unkillable processes, drain all available CPU/memory, and render the machine unrebootable. This only affects Ubuntu 6.10. (CVE-2006-5648)

Fabio Massimo Di Nitto discovered a flaw in the alignment check exception handling on the powerpc platform. A local attacker could exploit this to cause a kernel panic and crash the machine.
(CVE-2006-5649)

Certain corrupted squashfs file system images caused a memory allocation to be freed twice. By mounting a specially crafted squashfs file system, a local attacker could exploit this to crash the kernel.
This does not affect Ubuntu 5.10. (CVE-2006-5701)

An integer overflow was found in the get_fdb_entries() function of the network bridging code. By executing a specially crafted ioctl, a local attacker could exploit this to execute arbitrary code with root privileges. (CVE-2006-5751).

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-2005-4093     Olof Johansson reported a local DoS (Denial of Service)     vulnerability on the PPC970 platform. Unprivileged users     can hang the system by executing the 'attn' instruction,     which was not being disabled at boot.

  - CVE-2006-4538     Kirill Korotaev reported a local DoS (Denial of Service)     vulnerability on the ia64 and sparc architectures. A     user could cause the system to crash by executing a     malformed ELF binary due to insufficient verification of     the memory layout.

  - CVE-2006-4997     ADLab Venustech Info Ltd reported a potential remote DoS     (Denial of Service) vulnerability in the IP over ATM     subsystem. A remote system could cause the system to     crash by sending specially crafted packets that would     trigger an attempt to free an already-freed pointer     resulting in a system crash.

  - CVE-2006-5174     Martin Schwidefsky reported a potential leak of     sensitive information on s390 systems. The     copy_from_user function did not clear the remaining     bytes of the kernel buffer after receiving a fault on     the userspace address, resulting in a leak of     uninitialized kernel memory. A local user could exploit     this by appending to a file from a bad address.

  - CVE-2006-5649     Fabio Massimo Di Nitto reported a potential remote DoS     (Denial of Service) vulnerability on powerpc systems.
    The alignment exception only checked the exception table     for -EFAULT, not for other errors. This can be exploited     by a local user to cause a system crash (panic).

  - CVE-2006-5871     Bill Allombert reported that various mount options are     ignored by smbfs when UNIX extensions are enabled. This     includes the uid, gid and mode options. Client systems     would silently use the server-provided settings instead     of honoring these options, changing the security model.
    This update includes a fix from Haroldo Gamal that     forces the kernel to honor these mount options. Note     that, since the current versions of smbmount always pass     values for these options to the kernel, it is not     currently possible to activate unix extensions by     omitting mount options. However, this behavior is     currently consistent with the current behavior of the     next Debian release, 'etch'.

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-2006-3741     Stephane Eranian discovered a local DoS (Denial of     Service) vulnerability on the ia64 architecture. A local     user could exhaust the available file descriptors by     exploiting a counting error in the permonctl() system     call.

  - CVE-2006-4538     Kirill Korotaev reported a local DoS (Denial of Service)     vulnerability on the ia64 and sparc architectures. A     user could cause the system to crash by executing a     malformed ELF binary due to insufficient verification of     the memory layout.

  - CVE-2006-4813     Dmitriy Monakhov reported a potential memory leak in the
    __block_prepare_write function. __block_prepare_write     does not properly sanitize kernel buffers during error     recovery, which could be exploited by local users to     gain access to sensitive kernel memory.

  - CVE-2006-4997     ADLab Venustech Info Ltd reported a potential remote DoS     (Denial of Service) vulnerability in the IP over ATM     subsystem. A remote system could cause the system to     crash by sending specially crafted packets that would     trigger an attempt to free an already-freed pointer     resulting in a system crash.

  - CVE-2006-5174     Martin Schwidefsky reported a potential leak of     sensitive information on s390 systems. The     copy_from_user function did not clear the remaining     bytes of the kernel buffer after receiving a fault on     the userspace address, resulting in a leak of     uninitialized kernel memory. A local user could exploit     this by appending to a file from a bad address.

  - CVE-2006-5619     James Morris reported a potential local DoS (Denial of     Service) vulnerability that could be used to hang or     oops a system. The seqfile handling for     /proc/net/ip6_flowlabel has a flaw that can be exploited     to cause an infinite loop by reading this file after     creating a flowlabel.

  - CVE-2006-5649     Fabio Massimo Di Nitto reported a potential remote DoS     (Denial of Service) vulnerability on powerpc systems.
    The alignment exception only checked the exception table     for -EFAULT, not for other errors. This can be exploited     by a local user to cause a system crash (panic).

  - CVE-2006-5751     Eugene Teo reported a vulnerability in the     get_fdb_entries function that could potentially be     exploited to allow arbitrary code execution with     escalated privileges.

  - CVE-2006-5871     Bill Allombert reported that various mount options are     ignored by smbfs when UNIX extensions are enabled. This     includes the uid, gid and mode options. Client systems     would silently use the server-provided settings instead     of honoring these options, changing the security model.
    This update includes a fix from Haroldo Gamal that     forces the kernel to honor these mount options. Note     that, since the current versions of smbmount always pass     values for these options to the kernel, it is not     currently possible to activate unix extensions by     omitting mount options. However, this behavior is     currently consistent with the current behavior of the     next Debian release, 'etch'.

Updated kernel packages are now available as part of ongoing support and maintenance of Red Hat Enterprise Linux version 4. This is the second regular update.

This update 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.

This is the second regular kernel update to Red Hat Enterprise Linux 4.

New features introduced in this update include: - Audit support - systemtap - kprobes, relayfs - Keyring support - iSCSI Initiator - iscsi_sfnet 4:0.1.11-1 - Device mapper multipath support - Intel dual core support - esb2 chipset support - Increased exec-shield coverage - Dirty page tracking for HA systems - Diskdump -- allow partial diskdumps and directing to swap

There were several bug fixes in various parts of the kernel. The ongoing effort to resolve these problems has resulted in a marked improvement in the reliability and scalability of Red Hat Enterprise Linux 4.

The following security bugs were fixed in this update, detailed below with corresponding CAN names available from the Common Vulnerabilities and Exposures project (cve.mitre.org) :

  - flaws in ptrace() syscall handling on 64-bit systems     that allowed a local user to cause a denial of service     (crash) (CVE-2005-0756, CVE-2005-1761, CVE-2005-1762,     CVE-2005-1763)

  - flaws in IPSEC network handling that allowed a local     user to cause a denial of service or potentially gain     privileges (CVE-2005-2456, CVE-2005-2555)

  - a flaw in sendmsg() syscall handling on 64-bit systems     that allowed a local user to cause a denial of service     or potentially gain privileges (CVE-2005-2490)

  - a flaw in sendmsg() syscall handling that allowed a     local user to cause a denial of service by altering     hardware state (CVE-2005-2492)

  - a flaw that prevented the topdown allocator from     allocating mmap areas all the way down to address zero     (CVE-2005-1265)

  - flaws dealing with keyrings that could cause a local     denial of service (CVE-2005-2098, CVE-2005-2099)

  - a flaw in the 4GB split patch that could allow a local     denial of service (CVE-2005-2100)

  - a xattr sharing bug in the ext2 and ext3 file systems     that could cause default ACLs to disappear     (CVE-2005-2801)

  - a flaw in the ipt_recent module on 64-bit architectures     which could allow a remote denial of service     (CVE-2005-2872)

The following device drivers have been upgraded to new versions :

qla2100 --------- 8.00.00b21-k to 8.01.00b5-rh2 qla2200 --------- 8.00.00b21-k to 8.01.00b5-rh2 qla2300 --------- 8.00.00b21-k to 8.01.00b5-rh2 qla2322 --------- 8.00.00b21-k to 8.01.00b5-rh2 qla2xxx
--------- 8.00.00b21-k to 8.01.00b5-rh2 qla6312 --------- 8.00.00b21-k to 8.01.00b5-rh2 megaraid_mbox --- 2.20.4.5 to 2.20.4.6 megaraid_mm
----- 2.20.2.5 to 2.20.2.6 lpfc ------------ 0:8.0.16.6_x2 to 0:8.0.16.17 cciss ----------- 2.6.4 to 2.6.6 ipw2100 --------- 1.0.3 to 1.1.0 tg3 ------------- 3.22-rh to 3.27-rh e100 ------------ 3.3.6-k2-NAPI to 3.4.8-k2-NAPI e1000 ----------- 5.6.10.1-k2-NAPI to 6.0.54-k2-NAPI 3c59x ----------- LK1.1.19 mptbase --------- 3.01.16 to 3.02.18 ixgb ------------ 1.0.66 to 1.0.95-k2-NAPI libata ---------- 1.10 to 1.11 sata_via -------- 1.0 to 1.1 sata_ahci ------- 1.00 to 1.01 sata_qstor ------ 0.04 sata_sil -------- 0.8 to 0.9 sata_svw
-------- 1.05 to 1.06 s390: crypto ---- 1.31 to 1.57 s390: zfcp ------ s390: CTC-MPC --- s390: dasd ------- s390: cio ------- s390: qeth
------

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 Redhat Enterprise Linux 4 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2005:514 advisory.

  - security flaw (CVE-2005-0756, CVE-2005-1265, CVE-2005-1761, CVE-2005-1762, CVE-2005-1763, CVE-2005-2098,     CVE-2005-2099, CVE-2005-2100, CVE-2005-2456, CVE-2005-2490, CVE-2005-2492, CVE-2005-2555, CVE-2005-2801,     CVE-2005-2872, CVE-2005-3105, CVE-2005-3274, CVE-2005-3275, CVE-2006-5871)

  - Fix ipv6 exthdr bug causing Oops (CVE-2005-4886)

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

The remote CentOS system is missing a security update which has been documented in Red Hat advisory RHSA-2005-514.

ID	Name	Product	Family	Severity
27981	Ubuntu 5.10 / 6.06 LTS / 6.10 : linux-source-2.6.12/-2.6.15/-2.6.17 vulnerabilities (USN-395-1)	Nessus	Ubuntu Local Security Checks	high
23911	Debian DSA-1237-1 : kernel-source-2.4.27 - several vulnerabilities	Nessus	Debian Local Security Checks	high
23846	Debian DSA-1233-1 : kernel-source-2.6.8 - several vulnerabilities	Nessus	Debian Local Security Checks	high
21943	CentOS 4 : kernel (CESA-2005:514)	Nessus	CentOS Local Security Checks	high
19989	RHEL 4 : Updated kernel packages available for Red Hat Enterprise Linux 4 Update 2 (Important) (RHSA-2005:514)	Nessus	Red Hat Local Security Checks	high
801409	CentOS RHSA-2005-514 Security Check	Log Correlation Engine	Generic	high

Detections

Analytics

CVE-2006-5871

critical

Tenable Plugins

high

high

high

high

high

high