Format string vulnerability in Hashcash 1.16 allows remote attackers to cause a denial of service (memory consumption) and possibly execute arbitrary code via format string specifiers in a reply address, which is not properly handled when printing the header.

Heap-based buffer overflow in the array_push function in hashcash.c for Hashcash before 1.21 might allow attackers to execute arbitrary code via crafted entries.

PHP remote file inclusion vulnerability in server.php in the Hashcash Component (com_hashcash) 1.2.1 for Joomla! allows remote attackers to execute arbitrary PHP code via a URL in the mosConfig_absolute_path parameter.