Zen Cart 1.3.8a, 1.3.8, and earlier does not require administrative authentication for admin/sqlpatch.php, which allows remote attackers to execute arbitrary SQL commands via the query_string parameter in an execute action, in conjunction with a PATH_INFO of password_forgotten.php, related to a "SQL Execution" issue.
https://exchange.xforce.ibmcloud.com/vulnerabilities/51317
http://www.zen-cart.com/forum/showthread.php?t=130161
http://www.zen-cart.com/forum/attachment.php?attachmentid=5965