RHSA-2011:0414 - Security Advisory

Topic

Updated policycoreutils packages that fix one security issue are now
available for Red Hat Enterprise Linux 6.

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 policycoreutils packages contain the core utilities that are
required for the basic operation of a Security-Enhanced Linux (SELinux)
system and its policies.

It was discovered that the seunshare utility did not enforce proper file
permissions on the directory used as an alternate temporary directory
mounted as /tmp/. A local user could use this flaw to overwrite files or,
possibly, execute arbitrary code with the privileges of a setuid or
setgid application that relies on proper /tmp/ permissions, by running that
application via seunshare. (CVE-2011-1011)

Red Hat would like to thank Tavis Ormandy for reporting this issue.

This update also introduces the following changes:

• The seunshare utility was moved from the main policycoreutils subpackage

to the policycoreutils-sandbox subpackage. This utility is only required
by the sandbox feature and does not need to be installed by default.

• Updated selinux-policy packages that add the SELinux policy changes

required by the seunshare fixes.

All policycoreutils users should upgrade to these updated packages, which
correct this issue.

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 Workstation 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 6 i386
• Red Hat Enterprise Linux Workstation 6 x86_64
• Red Hat Enterprise Linux Desktop 6 x86_64
• Red Hat Enterprise Linux Desktop 6 i386
• Red Hat Enterprise Linux Server - Extended Life Cycle Support (for IBM z Systems) 6 s390x
• Red Hat Enterprise Linux Server - Extended Life Cycle Support Extension 6 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support Extension 6 i386
• Red Hat Enterprise Linux Server - Extended Life Cycle Support Extension (for IBM z Systems) 6 s390x

Fixes

• BZ - 633544 - CVE-2011-1011 policycoreutils: insecure temporary directory handling in seunshare

CVEs

• CVE-2011-1011

References

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