Updated XFree86 packages that fix a libXpm integer overflow flaw and a number of bugs are now available. This update has been rated as having moderate security impact by the CentOS Security Response Team.
XFree86 is an open source implementation of the X Window System. It provides the basic low level functionality which full-fledged graphical user interfaces (GUIs) such as GNOME and KDE are designed upon. An integer overflow flaw was found in libXpm, which is used by some applications for loading of XPM images. An attacker could create a malicious XPM file that would execute arbitrary code if opened by a victim using an application linked to the vulnerable library. The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CAN-2005-0605 to this issue. XFree86 4.1.0 was not functional on systems that did not have a legacy keyboard controller (8042). During startup, the X server would attempt to update registers on the 8042 controller, but if that chip was not present, the X server would hang during startup. This new release has a workaround so that the access to those registers time out if they are not present. A bug in libXaw could cause applications to segfault on 64-bit systems under certain circumstances. This has been fixed with a patch backported from XFree86 4.3.0. Xlib contained a memory leak caused by double allocation, which has been fixed in XFree86 4.3.0 using backported patch. All users of XFree86 should upgrade to these updated packages, which resolve these issues.