4.91. libpng

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

Security Fixes

CVE-2011-2690
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.

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.
CVE-2011-2692
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.
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.