Updated X.org packages that correct a flaw in X.Org's composite extension
are now available for Red Hat Enterprise Linux 4.
This update has been rated as having moderate security impact by the Red
Hat Security Response Team.
X.org is an open source implementation of the X Window System. It provides
the basic low-level functionality that full-fledged graphical user
interfaces are designed upon.
A flaw was found in the way X.Org's composite extension handles 32 bit
color depth windows while running in 16 bit color depth mode. If an X.org
server has enabled the composite extension, it may be possible for a
malicious authorized client to cause a denial of service (crash) or
potentially execute arbitrary code with the privileges of the X.org server.
Please note this flaw can only be triggered when using a compositing window
manager. Red Hat Enterprise Linux 4 does not ship with a compositing window
Users of X.org should upgrade to these updated packages, which contain a
backported patch and are not vulnerable to these issues.