X Font Server: Multiple Vulnerabilities
Gentoo Linux Security Advisory
||GLSA 200710-11 / xfs
||October 12, 2007
||October 12, 2007: 01
All supported architectures
Three vulnerabilities have been discovered in the X Font Server possibly
allowing local attackers to gain elevated privileges.
The X.Org X11 X Font Server provides a standard mechanism for an X
server to communicate with a font renderer.
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
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,
There is no known workaround at this time.
All X Font Server users should upgrade to the latest version:
Code Listing 3.1: Resolution
# emerge --sync
# emerge --ask --oneshot --verbose ">=x11-apps/xfs-1.0.5"