Code:  PHP_FUNCTION(mcrypt_module_is_block_algorithm)
 {
 	MCRYPT_GET_MODE_DIR_ARGS(algorithms_dir)
 	if (mcrypt_module_is_block_algorithm(module, dir) == 1) {
 		RETURN_TRUE;
 	} else {
		RETURN_FALSE;
	}
}

Vulnerability Type: DoS Overflow 
CWE ID: CWE-190
Summary: Multiple integer overflows in mcrypt.c in the mcrypt extension in PHP before 5.5.37, 5.6.x before 5.6.23, and 7.x before 7.0.8 allow remote attackers to cause a denial of service (heap-based buffer overflow and application crash) or possibly have unspecified other impact via a crafted length value, related to the (1) mcrypt_generic and (2) mdecrypt_generic functions.
Commit Message: Fix bug #72455:  Heap Overflow due to integer overflows