+++ This bug was initially created as a clone of Bug #242903 +++
Local exploitation of a race condition vulnerability in init.d XFS (X Font
Server) script allows an attacker to elevate their privileges to root.
The XFS script is vulnerable to a race condition when it is started by init, or
by a system administrator. Specifically, it insecurely changes the file
permissions of a temporary file. This allows an attacker to make any file on the
system world writable.
Successful exploitation of this vulnerability results in an attacker gaining
root privileges on the affected system. However, in order to exploit this, it is
necessary for either the system to be rebooted, or for the administrator to
manually restart the XFS.
This was fixed in the XFS init script in Red Hat Enterprise Linux 4 and 5:
but it seems that the change never made it to Fedora. Init script in Fedora still does mkdir/chown/chmod and not mkdir -m 1777 as is done in RHEL scripts. Affects all current Fedora versions - F9 - F11/rawhide. This should be fix, so we do not re-introduce the bug in RHEL6.
Fixed in F-9 through rawhide, updates to follow shortly.
xorg-x11-xfs-1.0.5-2.1.fc9 has been pushed to the Fedora 9 stable repository. If problems still persist, please make note of it in this bug report.
xorg-x11-xfs-1.0.5-3.1.fc10 has been pushed to the Fedora 10 stable repository. If problems still persist, please make note of it in this bug report.