httpd.c in httpd in the management GUI in DD-WRT 24 sp1, and other versions before build 12533, allows remote attackers to execute arbitrary commands via shell metacharacters in a request to a cgi-bin/ URI.
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.