----------------------------------------------------------------------

Try a new way to discover vulnerabilities that ALREADY EXIST in your
IT infrastructure.

The Secunia NSI enables you to INSPECT, DISCOVER, and DOCUMENT
vulnerabilities in more than 4,700 different Windows applications.

Request your account, the Secunia Network Software Inspector (NSI):
http://secunia.com/network_software_inspector/

----------------------------------------------------------------------

TITLE:
X.Org X11 X Font Server Multiple Vulnerabilities

SECUNIA ADVISORY ID:
SA27040

VERIFY ADVISORY:
http://secunia.com/advisories/27040/

CRITICAL:
Less critical

IMPACT:
Privilege escalation

WHERE:
Local system

REVISION:
1.1 originally posted 2007-10-03

SOFTWARE:
X Window System 11 (X11) 7.x
http://secunia.com/product/8806/
X Window System 11 (X11) 6.x
http://secunia.com/product/3913/

DESCRIPTION:
Some vulnerabilities have been reported in the X.Org X11 X Font
Server (XFS), which can be exploited by malicious, local users to
gain escalated privileges.

1) An integer overflow exists within the handlers for the X protocol
requests "QueryXBitmaps" and "QueryXExtents", which do not correctly
check the "length" parameters before passing them to the
"build_range()" function. This can be exploited to cause a heap-based
buffer overflow by sending specially crafted "QueryXBitmaps" and
"QueryXExtents" requests to a vulnerable service.

2) An error exists within the handler for the X protocol requests
"QueryXBitmaps" and "QueryXExtents" when calling the "swap_char2b()"
function, which can be exploited to swap an arbitrary number of bytes
on the heap, resulting in a heap corruption.

Note: On certain systems (e.g. Sun Solaris), these vulnerabilities
may be remotely exploitable through port 7100/TCP.

The vulnerabilities are reported in X.Org XFS 1.0.4 (X11R7.2 and
X11R7.3) and prior.

SOLUTION:
Update to X.Org XFS 1.0.5.

PROVIDED AND/OR DISCOVERED BY:
Sean Larsson, VeriSign iDefense Labs

CHANGELOG:
2007-10-03: Added CVE reference.

ORIGINAL ADVISORY:
X.Org:
http://lists.freedesktop.org/archives/xorg-announce/2007-October/000416.html

iDefense Labs:
http://labs.idefense.com/intelligence/vulnerabilities/display.php?id=602

----------------------------------------------------------------------

About:
This Advisory was delivered by Secunia as a free service to help
everybody keeping their systems up to date against the latest
vulnerabilities.

Subscribe:
http://secunia.com/secunia_security_advisories/

Definitions: (Criticality, Where etc.)
http://secunia.com/about_secunia_advisories/


Please Note:
Secunia recommends that you verify all advisories you receive by
clicking the link.
Secunia NEVER sends attached files with advisories.
Secunia does not advise people to install third party patches, only
use those supplied by the vendor.

----------------------------------------------------------------------

Unsubscribe: Secunia Security Advisories
http://secunia.com/sec_adv_unsubscribe/?email=packet%40packetstormsecurity.org

----------------------------------------------------------------------