The ewirePC_Decrypt function in ewirepcfunctions.php in eWire Payment Client (ePC) 1.60 and 1.70 allows remote attackers to execute arbitrary commands via shell metacharacters in the paymentinfo parameter to simplePHPLinux/3payment_receive.php.
Improper Input Validation The product receives input or data, but it does
not validate or incorrectly validates that the input has the
properties that are required to process the data safely and
correctly.