TRENDnet TEW-827DRU devices through 2.06B04 contain a stack-based buffer overflow in the ssi binary. The overflow allows an authenticated user to execute arbitrary code by POSTing to apply.cgi via the action vlan_setting with a sufficiently long dns1 or dns 2 key.
https://github.com/HouseFuzz/reports/blob/main/trendnet/TEW827/vlan_setting/vlan_setting.md