RHEL 5 : kernel (RHSA-2011:1163)

This script is Copyright (C) 2013-2014 Tenable Network Security, Inc.


Synopsis :

The remote Red Hat host is missing one or more security updates.

Description :

Updated kernel packages that fix two security issues and three bugs
are now available for Red Hat Enterprise Linux 5.6 Extended Update
Support.

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.

This update includes backported fixes for two security issues. These
issues only affected users of Red Hat Enterprise Linux 5.6 Extended
Update Support, as they have already been addressed for users of Red
Hat Enterprise Linux 5 in the 5.7 update, RHSA-2011:1065.

This update fixes the following security issues :

* A flaw was found in the way the Xen hypervisor implementation
handled instruction emulation during virtual machine exits. A
malicious user-space process running in an SMP guest could trick the
emulator into reading a different instruction than the one that caused
the virtual machine to exit. An unprivileged guest user could trigger
this flaw to crash the host. This only affects systems with both an
AMD x86 processor and the AMD Virtualization (AMD-V) extensions
enabled. (CVE-2011-1780, Important)

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

This update also fixes the following bugs :

* A bug was found in the way the x86_emulate() function handled the
IMUL instruction in the Xen hypervisor. On systems without support for
hardware assisted paging (HAP), such as those running CPUs that do not
have support for (or those that have it disabled) Intel Extended Page
Tables (EPT) or AMD Virtualization (AMD-V) Rapid Virtualization
Indexing (RVI), this bug could cause fully-virtualized guests to crash
or lead to silent memory corruption. In reported cases, this issue
occurred when booting fully-virtualized Red Hat Enterprise Linux 6.1
guests with memory cgroups enabled. (BZ#712884)

* A bug in the way the ibmvscsi driver handled interrupts may have
prevented automatic path recovery for multipath devices. This bug only
affected 64-bit PowerPC systems. (BZ#720929)

* The RHSA-2009:1243 update introduced a regression in the way file
locking on NFS (Network File System) was handled. This caused
applications to hang if they made a lock request on a file on an NFS
version 2 or 3 file system that was mounted with the 'sec=krb5'
option. With this update, the original behavior of using mixed RPC
authentication flavors for NFS and locking requests has been restored.
(BZ#722854)

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

See also :

https://www.redhat.com/security/data/cve/CVE-2011-1780.html
https://www.redhat.com/security/data/cve/CVE-2011-2525.html
https://rhn.redhat.com/errata/RHSA-2011-1065.html
https://rhn.redhat.com/errata/RHSA-2009-1243.html
http://rhn.redhat.com/errata/RHSA-2011-1163.html

Solution :

Update the affected packages.

Risk factor :

High / CVSS Base Score : 7.2
(CVSS2#AV:L/AC:L/Au:N/C:C/I:C/A:C)
CVSS Temporal Score : 6.3
(CVSS2#E:ND/RL:OF/RC:C)
Public Exploit Available : false

Family: Red Hat Local Security Checks

Nessus Plugin ID: 63996 ()

Bugtraq ID: 48610
48641

CVE ID: CVE-2011-1780
CVE-2011-2525