RHSA-2010:0793 - Security Advisory

Topic

Updated glibc packages that fix one security issue 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 glibc packages contain the standard C libraries used by multiple
programs on the system. These packages contain the standard C and the
standard math libraries. Without these two libraries, a Linux system cannot
function properly.

It was discovered that the glibc dynamic linker/loader did not perform
sufficient safety checks when loading dynamic shared objects (DSOs) to
provide callbacks for its auditing API during the execution of
privileged programs. A local attacker could use this flaw to escalate
their privileges via a carefully-chosen system DSO library containing
unsafe constructors. (CVE-2010-3856)

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

All users should upgrade to these updated packages, which contain a
backported patch to 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
http://kbase.redhat.com/faq/docs/DOC-11259

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 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 Power, big endian 5 ppc
• Red Hat Enterprise Linux Server from RHUI 5 x86_64
• Red Hat Enterprise Linux Server from RHUI 5 i386

Fixes

• BZ - 645672 - CVE-2010-3856 glibc: ld.so arbitrary DSO loading via LD_AUDIT in setuid/setgid programs

CVEs

• CVE-2010-3856

References

• http://www.redhat.com/security/updates/classification/#important