5 - RHSA-2013:0168

Problem Description:

Updated kernel packages that fix three security issues and several bugs are now available for Red Hat Enterprise Linux 5.

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.

2. Relevant releases/architectures:

Red Hat Enterprise Linux (v. 5 server) - i386, ia64, noarch, ppc, s390x, x86_64 Red Hat Enterprise Linux Desktop (v. 5 client) - i386, noarch, x86_64

3. Description:

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

This update fixes the following security issues:

* It was found that the Xen hypervisor implementation did not perform range checking on the guest provided values in multiple hypercalls. A privileged guest user could use this flaw to trigger long loops, leading to a denial of service (Xen hypervisor hang). (CVE-2012-5515, Moderate)

* It was found that when running a 32-bit binary that uses a large number of shared libraries, one of the libraries would always be loaded at a predictable address in memory. An attacker could use this flaw to bypass the Address Space Layout Randomization (ASLR) security feature. (CVE-2012-1568, Low)

* A flaw was found in the way the Linux kernel's IPv6 implementation handled overlapping, fragmented IPv6 packets. A remote attacker could potentially use this flaw to bypass protection mechanisms (such as a firewall or intrusion detection system (IDS)) when sending network packets to a target system. (CVE-2012-4444, Low)

Red Hat would like to thank the Xen project for reporting CVE-2012-5515, and Antonios Atlasis working with Beyond Security's SecuriTeam Secure Disclosure program and Loganaden Velvindron of AFRINIC for reporting CVE-2012-4444.

This update also fixes several bugs. Space precludes documenting all of these changes in this advisory. Documentation for these changes will be available shortly from the Red Hat Enterprise Linux 5.9 Technical Notes document linked to in the References section.

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.

4. 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.

5. Bugs fixed (http://bugzilla.redhat.com/):

804947 - CVE-2012-1568 kernel: execshield: predictable ascii armour base address 874835 - CVE-2012-4444 kernel: net: acceptation of overlapping ipv6 fragments 877397 - CVE-2012-5515 kernel: xen: Several memory hypercall operations allow invalid extent order values