GLSA 200609-07: LibXfont, monolithic X.org: Multiple integer overflows

http://security.gentoo.org/

Severity:	high
Title:	LibXfont, monolithic X.org: Multiple integer overflows
Date:	09/13/2006
Bugs:	#145513
ID:	200609-07

Synopsis

Some buffer overflows were discovered in the CID font parser, potentially resulting in the execution of arbitrary code with elevated privileges.

Background

libXfont is the X.Org Xfont library, some parts are based on the FreeType code base.

Affected packages

Package	Vulnerable	Unaffected	Architecture(s)
x11-libs/libXfont	< 1.2.1	>= 1.2.1	All supported architectures
x11-base/xorg-x11	< 7.0	>= 7.0	All supported architectures

Description

Several integer overflows have been found in the CID font parser.

Impact

A remote attacker could exploit this vulnerability by enticing a user to load a malicious font file resulting in the execution of arbitrary code with the permissions of the user running the X server which typically is the root user. A local user could exploit this vulnerability to gain elevated privileges.

Workaround

Disable CID-encoded Type 1 fonts by removing the "type1" module and replacing it with the "freetype" module in xorg.conf.

Resolution

All libXfont users should upgrade to the latest version:

    # emerge --sync
    # emerge --ask --oneshot --verbose ">=x11-libs/libXfont-1.2.1"

All monolithic X.org users are advised to migrate to modular X.org.

References

Availability

This GLSA and any updates to it are available for viewing at the Gentoo Security Website: http://security.gentoo.org/glsa/glsa-200609-07.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.