GLSA 200710-16: X.Org X server: Composite local privilege escalation

http://security.gentoo.org/

Severity:	high
Title:	X.Org X server: Composite local privilege escalation
Date:	10/14/2007
Bugs:	#191964
ID:	200710-16

Synopsis

A vulnerability has been discovered in the Composite extension of the X.Org X server, allowing for a local privilege escalation.

Background

The X Window System is a graphical windowing system based on a client/server model.

Affected packages

Package	Vulnerable	Unaffected	Architecture(s)
x11-base/xorg-server	< 1.3.0.0-r1	>= 1.3.0.0-r1	All supported architectures

Description

Aaron Plattner discovered a buffer overflow in the compNewPixmap() function when copying data from a large pixel depth pixmap into a smaller pixel depth pixmap.

Impact

A local attacker could execute arbitrary code with the privileges of the user running the X server, typically root.

Workaround

Disable the Composite extension by setting ' Option "Composite" "disable" ' in the Extensions section of xorg.conf.

Note: This could affect the functionality of some applications.

Resolution

All X.Org X server users should upgrade to the latest version:

    # emerge --sync
    # emerge --ask --oneshot --verbose ">=x11-base/xorg-server-1.3.0.0-r1"

References

CVE-2007-4730

Availability

This GLSA and any updates to it are available for viewing at the Gentoo Security Website: http://security.gentoo.org/glsa/glsa-200710-16.xml

Concerns?

Security is a primary focus of Gentoo Linux and ensuring the confidentiality and security of our users machines is of utmost importance to us. Any security concerns should be addressed to security@gentoo.org or alternatively, you may file a bug at https://bugs.gentoo.org.