cgi_test.cgi in AirLive BU-2015 with firmware 1.03.18, BU-3026 with firmware 1.43, and MD-3025 with firmware 1.81 allows remote attackers to execute arbitrary OS commands via shell metacharacters after an "&" (ampersand) in the write_mac write_pid, write_msn, write_tan, or write_hdv parameter.