RHSA-2011:1104 - Security Advisory

Topic

Updated libpng 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 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.

Description

The libpng packages contain a library of functions for creating and
manipulating PNG (Portable Network Graphics) image format files.

A buffer overflow flaw was found in the way libpng processed certain PNG
image files. An attacker could create a specially-crafted PNG image that,
when opened, could cause an application using libpng to crash or,
potentially, execute arbitrary code with the privileges of the user running
the application. (CVE-2011-2690)

Note: The application behavior required to exploit CVE-2011-2690 is rarely
used. No application shipped with Red Hat Enterprise Linux behaves this
way, for example.

An uninitialized memory read issue was found in the way libpng processed
certain PNG images that use the Physical Scale (sCAL) extension. An
attacker could create a specially-crafted PNG image that, when opened,
could cause an application using libpng to crash. (CVE-2011-2692)

Users of libpng should upgrade to these updated packages, which contain
backported patches to correct these issues. All running applications using
libpng must be restarted for the 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/kb/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 - 720607 - CVE-2011-2690 libpng: buffer overwrite in png_rgb_to_gray
• BZ - 720612 - CVE-2011-2692 libpng: Invalid read when handling empty sCAL chunks

CVEs

• CVE-2011-2692
• CVE-2011-2690

References

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