Updated libtiff packages that fix one security issue and one bug are now available for Red Hat Enterprise Linux 4, 5, and 6. The Red Hat Security Response Team has rated this update as having important security impact. A Common Vulnerability Scoring System base score, which gives a detailed severity rating, is available from the CVE link in the References section. Description The libtiff packages contain a library of functions for manipulating Tagged Image File Format files. A heap-based buffer overflow flaw was found in the way libtiff processed certain TIFF files encoded with a 4-bit run-length encoding scheme from ThunderScan. An attacker could use this flaw to create a specially-crafted TIFF file that, when opened, would cause an application linked against libtiff to crash or, possibly, execute arbitrary code. This update also fixes the following bug: The RHSA-2011:0318 libtiff update introduced a regression that prevented certain TIFF Internet Fax image files, compressed with the CCITT Group 4 compression algorithm, from being read. All libtiff users should upgrade to these updated packages, which contain a backported patch to resolve these issues. All running applications linked against libtiff must be restarted for this update to take effect.