The gdImageCrop function in ext/gd/gd.c in PHP 5.5.x before 5.5.9 does not check return values, which allows remote attackers to cause a denial of service (application crash) or possibly have unspecified other impact via invalid imagecrop arguments that lead to use of a NULL pointer as a return value, a different vulnerability than CVE-2013-7226. http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2013-7327
