TRENDnet TEW-812DRU router allows remote authenticated users to execute arbitrary commands via shell metacharacters in the (1) wan network prefix to internet/ipv6.asp; (2) remote port to adm/management.asp; (3) pptp username, (4) pptp password, (5) ip, (6) gateway, (7) l2tp username, or (8) l2tp password to internet/wan.asp; (9) NtpDstStart, (10) NtpDstEnd, or (11) NtpDstOffset to adm/time.asp; or (12) device url to adm/management.asp.  NOTE: vectors 9, 10, and 11 can be exploited by unauthenticated remote attackers by leveraging CVE-2013-3098.