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

[GLSA]

Gentoo Linux Security Advisory

Title: X.Org X server: Composite local privilege escalation (GLSA 200710-16)
Severity: high
Exploitable: local
Date: October 14, 2007
Bug(s): #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: x11-base/xorg-server
Vulnerable: < 1.3.0.0-r1
Unaffected: >= 1.3.0.0-r1
Architectures: 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: