The following flaw has been fixed in the Apache HTTP Server:

"A flaw was found in the WinNT MPM in httpd versions 2.4.1 to 2.4.9, when using the default AcceptFilter for that platform. A remote attacker could send carefully crafted requests that would leak memory and eventually lead to a denial of service against the server."

External References:

http://httpd.apache.org/security/vulnerabilities_24.html