RHSA-2013:0621 - Security Advisory

Topic

Updated kernel packages that fix two security issues are now available
for Red Hat Enterprise Linux 5.

The Red Hat Security Response Team has rated this update as having
important security impact. A Common Vulnerability Scoring System (CVSS)
base score, which gives a detailed severity rating, is available from the
CVE link in the References section.

Description

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

This update fixes the following security issues:

• A flaw was found in the way file permission checks for the

"/dev/cpu/[x]/msr" files were performed in restricted root environments
(for example, when using a capability-based security model). A local user
with the ability to write to these files could use this flaw to escalate
their privileges to kernel level, for example, by writing to the
SYSENTER_EIP_MSR register. (CVE-2013-0268, Important)

• A race condition was found in the way the Linux kernel's ptrace

implementation handled PTRACE_SETREGS requests when the debuggee was woken
due to a SIGKILL signal instead of being stopped. A local, unprivileged
user could use this flaw to escalate their privileges. (CVE-2013-0871,
Important)

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

Solution

Before applying this update, make sure all previously-released errata
relevant to your system have been applied.

This update is available via the Red Hat Network. Details on how to
use the Red Hat Network to apply this update are available at
https://access.redhat.com/knowledge/articles/11258

To install kernel packages manually, use "rpm -ivh [package]". Do not
use "rpm -Uvh" as that will remove the running kernel binaries from
your system. You may use "rpm -e" to remove old kernels after
determining that the new kernel functions properly on your system.

Affected Products

• Red Hat Enterprise Linux Server 5 x86_64
• Red Hat Enterprise Linux Server 5 ia64
• Red Hat Enterprise Linux Server 5 i386
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 5.9 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 5.9 ia64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 5.9 i386
• Red Hat Enterprise Linux Server - AUS 5.9 ia64
• Red Hat Enterprise Linux Workstation 5 x86_64
• Red Hat Enterprise Linux Workstation 5 i386
• Red Hat Enterprise Linux Desktop 5 x86_64
• Red Hat Enterprise Linux Desktop 5 i386
• Red Hat Enterprise Linux for IBM z Systems 5 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 5.9 s390x
• Red Hat Enterprise Linux for Power, big endian 5 ppc
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 5.9 ppc
• Red Hat Enterprise Linux Server from RHUI 5 x86_64
• Red Hat Enterprise Linux Server from RHUI 5 i386
• Red Hat Enterprise Linux Server - Extended Update Support from RHUI 5.9 x86_64
• Red Hat Enterprise Linux Server - Extended Update Support from RHUI 5.9 i386
• Red Hat Enterprise Linux Server - AUS 5.9 x86_64
• Red Hat Enterprise Linux Server - AUS 5.9 i386

Fixes

• BZ - 908693 - CVE-2013-0268 kernel: x86/msr: /dev/cpu/*/msr local privilege escalation
• BZ - 911937 - CVE-2013-0871 kernel: race condition with PTRACE_SETREGS

CVEs

• CVE-2013-0871
• CVE-2013-0268

References

• https://access.redhat.com/security/updates/classification/#important