Race condition in the mod_auth_shadow module for the Apache HTTP Server allows remote attackers to bypass authentication, and read and possibly modify data, via vectors related to improper interaction with an external helper application for validation of credentials.
https://bugzilla.redhat.com/show_bug.cgi?id=578168
http://www.vupen.com/english/advisories/2010/1148
http://www.vupen.com/english/advisories/2010/0908
http://www.securityfocus.com/bid/39538
http://www.mandriva.com/security/advisories?name=MDVSA-2010:081
http://secunia.com/advisories/39823
http://lists.fedoraproject.org/pipermail/package-announce/2010-May/041340.html
http://lists.fedoraproject.org/pipermail/package-announce/2010-May/041326.html