An updated xorg-x11-server-utils package that fixes one security issue is now available for Red Hat Enterprise Linux 5 and 6.

The Red Hat Security Response Team has rated this update as having moderate 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.

The xorg-x11-server-utils package contains a collection of utilities used to modify and query the runtime configuration of the X.Org server. X.Org is an open source implementation of the X Window System.

A flaw was found in the X.Org X server resource database utility, xrdb. Certain variables were not properly sanitized during the launch of a user's graphical session, which could possibly allow a remote attacker to execute arbitrary code with root privileges, if they were able to make the display manager execute xrdb with a specially-crafted X client hostname. For example, by configuring the hostname on the target system via a crafted DHCP reply, or by using the X Display Manager Control Protocol (XDMCP) to connect to that system from a host that has a special DNS name. (CVE-2011-0465)

Red Hat would like to thank Matthieu Herrb for reporting this issue. Upstream acknowledges Sebastian Krahmer of the SuSE Security Team as the original reporter.

Users of xorg-x11-server-utils should upgrade to this updated package, which contains a backported patch to resolve this issue. All running X.Org server instances must be restarted for this update to take effect.