{ "dataType": "CVE_RECORD", "cveMetadata": { "state": "PUBLISHED", "cveId": "CVE-2021-27137", "assignerOrgId": "8254265b-2729-46b6-b9e3-3dfca2d5bfca", "assignerShortName": "mitre", "dateUpdated": "2026-07-22T03:55:45.793Z", "dateReserved": "2021-02-10T00:00:00.000Z", "datePublished": "2026-07-16T00:00:00.000Z" }, "containers": { "cna": { "affected": [ { "defaultStatus": "unaffected", "product": "DD-WRT", "vendor": "DD-WRT", "versions": [ { "lessThan": "45724", "status": "affected", "version": "0", "versionType": "custom" } ] } ], "descriptions": [ { "lang": "en", "value": "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)." } ], "metrics": [ { "cvssV3_1": { "attackComplexity": "HIGH", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 8.1, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H", "version": "3.1" }, "format": "CVSS", "scenarios": [ { "lang": "en", "value": "GENERAL" } ] } ], "problemTypes": [ { "descriptions": [ { "cweId": "CWE-121", "description": "CWE-121 Stack-based Buffer Overflow", "lang": "en", "type": "CWE" } ] } ], "providerMetadata": { "orgId": "8254265b-2729-46b6-b9e3-3dfca2d5bfca", "shortName": "mitre", "dateUpdated": "2026-07-16T17:38:47.947Z" }, "references": [ { "url": "https://svn.dd-wrt.com/changeset/45724" }, { "url": "https://ssd-disclosure.com/ssd-advisory-dd-wrt-upnp-buffer-overflow/" }, { "url": "https://securityaffairs.com/193290/uncategorized/iot-botnet-c0xmo-adds-competitor-killing-capability.html" }, { "url": "https://www.bleepingcomputer.com/news/security/c0xmo-botnet-spreads-via-dd-wrt-router-flaw-kills-rival-malware/" }, { "url": "https://www.fortinet.com/blog/threat-research/inside-cross-platform-propagation-of-new-gafgyt-variant-c0xmo" } ], "x_generator": { "engine": "enrichogram 0.0.1" }, "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:a:dd-wrt:dd-wrt:*:*:*:*:*:*:*:*", "versionEndExcluding": "45724" } ] } ] } ] }, "adp": [ { "metrics": [ { "other": { "type": "ssvc", "content": { "timestamp": "2026-07-21T00:00:00+00:00", "options": [ { "Exploitation": "active" }, { "Automatable": "no" }, { "Technical Impact": "total" } ], "role": "CISA Coordinator", "version": "2.0.3", "id": "CVE-2021-27137" } } }, { "other": { "type": "kev", "content": { "dateAdded": "2026-07-21", "reference": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-27137" } } } ], "references": [ { "url": "https://ssd-disclosure.com/ssd-advisory-dd-wrt-upnp-buffer-overflow/", "tags": [ "exploit" ] }, { "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-27137", "tags": [ "government-resource" ] } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-07-22T03:55:45.793Z" }, "timeline": [ { "time": "2026-07-21T00:00:00.000Z", "lang": "en", "value": "CVE-2021-27137 added to CISA KEV" } ] } ] }, "dataVersion": "5.2" }