Synopsis

Important: libcgroup security update

Type/Severity

Security Advisory: Important

Topic

Updated libcgroup packages that fix two security issues are now available
for Red Hat Enterprise Linux 6.

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.

Description

The libcgroup packages provide tools and libraries to control and monitor
control groups.

A heap-based buffer overflow flaw was found in the way libcgroup converted
a list of user-provided controllers for a particular task into an array of
strings. A local attacker could use this flaw to escalate their privileges
via a specially-crafted list of controllers. (CVE-2011-1006)

It was discovered that libcgroup did not properly check the origin of
Netlink messages. A local attacker could use this flaw to send crafted
Netlink messages to the cgrulesengd daemon, causing it to put processes
into one or more existing control groups, based on the attacker's choosing,
possibly allowing the particular tasks to run with more resources (memory,
CPU, etc.) than originally intended. (CVE-2011-1022)

Red Hat would like to thank Nelson Elhage for reporting the CVE-2011-1006
issue.

All libcgroup users should upgrade to these updated packages, which contain
backported patches to correct these issues.

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/kb/docs/DOC-11259

Affected Products

• Red Hat Enterprise Linux Server 6 x86_64
• Red Hat Enterprise Linux Server 6 i386
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 6 i386
• Red Hat Enterprise Linux Workstation 6 x86_64
• Red Hat Enterprise Linux Workstation 6 i386
• Red Hat Enterprise Linux Desktop 6 x86_64
• Red Hat Enterprise Linux Desktop 6 i386
• Red Hat Enterprise Linux for IBM z Systems 6 s390x
• Red Hat Enterprise Linux for Power, big endian 6 ppc64
• Red Hat Enterprise Linux for Scientific Computing 6 x86_64
• Red Hat Enterprise Linux Server from RHUI 6 x86_64
• Red Hat Enterprise Linux Server from RHUI 6 i386
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 6 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support (for IBM z Systems) 6 s390x

Fixes

• BZ - 678107 - CVE-2011-1006 libcgroup: Heap-based buffer overflow by converting list of controllers for given task into an array of strings
• BZ - 680409 - CVE-2011-1022 libcgroup: Uncheck origin of NETLINK messages

CVEs

• CVE-2011-1022
• CVE-2011-1006

References