CVE-2020-10987

CVE-2020-10987 is an unauthenticated OS command injection flaw (CWE-78) in the goform/setUsbUnload endpoint of the Tenda AC15 AC1900 router, demonstrated on firmware version 15.03.05.19. An attacker triggers it by sending a crafted deviceName POST parameter to that endpoint, which is not properly sanitized before being used in a system command. Successful exploitation yields arbitrary remote code execution on the router, giving the attacker full control of the device and a foothold to pivot into the local network, as is typical for IoT botnet recruitment. Owners of Tenda AC15 routers are affected, with greatest risk on units whose web administration interface is reachable from the internet. Exploitation is confirmed in the wild: the flaw is in CISA's Known Exploited Vulnerabilities catalog (added 2021-11-03), carries a 79.8% EPSS score (top percentile), and a public proof of concept has been available since its 2020 disclosure; ransomware use is unknown.

What to do: Apply the latest Tenda AC15 firmware available from the vendor (newer than 15.03.05.19) per CISA's required action and vendor instructions. Until patched, disable or restrict WAN-side remote web administration to trusted source IPs, since the flaw is exploitable without credentials over the network. Check router HTTP logs for unexpected POST requests to /goform/setUsbUnload containing suspicious deviceName values, and monitor for botnet-style command activity.