CVE-2007-0988

The zend_hash_init function in PHP 5 before 5.2.1 and PHP 4 before 4.4.5,
when running on a 64-bit platform, allows context-dependent attackers to
cause a denial of service (infinite loop) by unserializing certain integer
expressions, which only cause 32-bit arguments to be used after the check
for a negative value, as demonstrated by an “a:2147483649:{” argument.