{"cve_id":"CVE-2021-27137","published":"2026-07-16T18:16:39.113000+00:00","last_modified":"2026-07-22T05:17:07.330000+00:00","vuln_status":"Analyzed","description":"An issue was discovered in router/upnp/src/ssdp.c in DD-WRT before 45724. 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).","cvss_version":"3.1","cvss_vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H","base_score":8.1,"base_severity":"HIGH","attack_vector":"NETWORK","privileges_req":"NONE","user_interaction":"NONE","scope":"UNCHANGED","impact_c":"HIGH","impact_i":"HIGH","impact_a":"HIGH","cwe_ids":["CWE-121"],"in_kev":true,"kev_date_added":"2026-07-21","kev_ransomware":false,"epss_score":0.03995,"epss_percentile":0.90521,"cap_rule_version":"0.1.1","stage":"INITIAL_ACCESS","req_access":"NONE","req_vector":"NETWORK","req_user_interaction":false,"grant_access":"USER","caps":["CODE_EXEC"],"terminal":false,"cap_confidence":"high","ingested_at":"2026-09-18T12:21:23.215311+00:00","first_seen":"2026-07-16T18:16:39.113000+00:00","kev_first_seen":"2026-07-21T00:00:00+00:00","novelty_score":0.0,"novelty_reasons":[],"novelty_at":null,"vendors":["dd-wrt"],"products":["dd-wrt"],"affected":[{"vendor":"dd-wrt","product":"dd-wrt","ranges":["< 45724"]}]}