CVE-2021-27137

An issue was discovered in router/upnp/src/ssdp.c in DD-WRT before An unsafe strcpy in the UPnP handling functionality allows an unauthenticated remote attacker to send a request that would overflow an internal fixed buffer. Exploitation requires the DD-WRT user to enable UPnP (which is off by default, and only listens on internal interfaces by default). This occurs in ssdp_msearch (reachable by an M-SEARCH request).

3 articles across 2 outlets · first covered Jun 8, 2026 · latest Jul 22, 2026