CVE-2011-3348
The mod_proxy_ajp module in the Apache HTTP Server before 2.2.21, when used with mod_proxy_balancer in certain configurations, allows remote attackers to cause a denial of service (temporary "error state" in the backend server) via a malformed HTTP request.
Date published : 2011-09-19
http://lists.apple.com/archives/security-announce/2012/Feb/msg00000.html