security/__init__.py in MoinMoin 1.9 through 1.9.4 does not properly handle group names that contain virtual group names such as "All," "Known," or "Trusted," which allows remote authenticated users with virtual group membership to be treated as a member of the group.
http://www.ubuntu.com/usn/USN-1604-1
http://www.openwall.com/lists/oss-security/2012/09/05/2
http://www.openwall.com/lists/oss-security/2012/09/04/4
http://www.debian.org/security/2012/dsa-2538
http://secunia.com/advisories/50885
http://secunia.com/advisories/50496
http://secunia.com/advisories/50474