Buffer overflow in the apache_request_headers function in sapi/cgi/cgi_main.c in PHP 5.4.x before 5.4.3 allows remote attackers to cause a denial of service (application crash) via a long string in the header of an HTTP request.
https://h20564.www2.hp.com/portal/site/hpsc/public/kb/docDisplay?docId=emr_na-c03839862
https://exchange.xforce.ibmcloud.com/vulnerabilities/75545
https://bugzilla.redhat.com/show_bug.cgi?id=820000
https://bugs.php.net/bug.php?id=61807
http://www.securityfocus.com/bid/53455
http://www.php.net/archive/2012.php#id2012-05-08-1