[ GLSA 200710-11 ] X Font Server: Multiple Vulnerabilities

[GLSA]

Gentoo Linux Security Advisory

Title: X Font Server: Multiple Vulnerabilities (GLSA 200710-11)
Severity: high
Exploitable: local
Date: October 12, 2007
Bug(s): #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: x11-apps/xfs
Vulnerable: < 1.0.5
Unaffected: >= 1.0.5
Architectures: 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: