GLSA 200710-11: X Font Server: Multiple Vulnerabilities

http://security.gentoo.org/

Severity:	high
Title:	X Font Server: Multiple Vulnerabilities
Date:	10/12/2007
Bugs:	#185660, #194606
ID:	200710-11

Synopsis

Three vulnerabilities have been discovered in the X Font Server possibly allowing local attackers to gain elevated privileges.

Background

The X.Org X11 X Font Server provides a standard mechanism for an X server to communicate with a font renderer.

Affected packages

Package	Vulnerable	Unaffected	Architecture(s)
x11-apps/xfs	< 1.0.5	>= 1.0.5	All supported architectures

Description

iDefense reported that the xfs init script does not correctly handle a race condition when setting permissions of a temporary file (CVE-2007-3103). Sean Larsson discovered an integer overflow vulnerability in the build_range() function possibly leading to a heap-based buffer overflow when handling "QueryXBitmaps" and "QueryXExtents" protocol requests (CVE-2007-4568). Sean Larsson also discovered an error in the swap_char2b() function possibly leading to a heap corruption when handling the same protocol requests (CVE-2007-4990).

Impact

The first issue would allow a local attacker to change permissions of arbitrary files to be world-writable by performing a symlink attack. The second and third issues would allow a local attacker to execute arbitrary code with privileges of the user running the X Font Server, usually xfs.

Workaround

There is no known workaround at this time.

Resolution

All X Font Server users should upgrade to the latest version:

    # emerge --sync
    # emerge --ask --oneshot --verbose ">=x11-apps/xfs-1.0.5"

References

Availability

This GLSA and any updates to it are available for viewing at the Gentoo Security Website: http://security.gentoo.org/glsa/glsa-200710-11.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.