HooToo TripMate Titan HT-TM05 and HT-05 routers with firmware 2.000.022 and 2.000.082 allow remote command execution via shell metacharacters in the mac parameter of a protocol.csp?function=set&fname=security&opt=mac_table request.
Source: NIST
CVE-2018-20841 (tripmate_titan_ht-tm05_firmware)