DD-WRT Stack-Based Buffer Overflow Vulnerability

Stored EPSS snapshot at this observation.

{
  "date": "2026-11-12",
  "epss": 0.03995,
  "percentile": 0.90664
}

Stored EPSS snapshot at this observation.

{
  "date": "2026-11-10",
  "epss": 0.03995,
  "percentile": 0.90606
}

Stored EPSS snapshot at this observation.

{
  "date": "2026-11-09",
  "epss": 0.03995,
  "percentile": 0.90594
}

Stored EPSS snapshot at this observation.

{
  "date": "2026-11-08",
  "epss": 0.03995,
  "percentile": 0.90588
}

Stored EPSS snapshot at this observation.

{
  "date": "2026-11-07",
  "epss": 0.03995,
  "percentile": 0.90582
}

Stored EPSS snapshot at this observation.

{
  "date": "2026-11-06",
  "epss": 0.03995,
  "percentile": 0.90566
}

Stored EPSS snapshot at this observation.

{
  "date": "2026-11-05",
  "epss": 0.03995,
  "percentile": 0.90558
}

Stored CNA snapshot at this observation.

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2021-27137",
                "options": [
                  {
                    "Exploitation": "active"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-07-21T00:00:00+00:00",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          },
          {
            "other": {
              "content": {
                "dateAdded": "2026-07-21",
                "reference": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-27137"
              },
              "type": "kev"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-07-22T03:55:45.793Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "references": [
          {
            "tags": [
              "exploit"
            ],
            "url": "https://ssd-disclosure.com/ssd-advisory-dd-wrt-upnp-buffer-overflow/"
          },
          {
            "tags": [
              "government-resource"
            ],
            "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-27137"
          }
        ],
        "timeline": [
          {
            "lang": "en",
            "time": "2026-07-21T00:00:00.000Z",
            "value": "CVE-2021-27137 added to CISA KEV"
          }
        ],
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "DD-WRT",
          "vendor": "DD-WRT",
          "versions": [
            {
              "lessThan": "45724",
              "status": "affected",
              "version": "0",
              "versionType": "custom"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:a:dd-wrt:dd-wrt:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "45724",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "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": {
        "dateUpdated": "2026-07-16T17:38:47.947Z",
        "orgId": "8254265b-2729-46b6-b9e3-3dfca2d5bfca",
        "shortName": "mitre"
      },
      "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"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "8254265b-2729-46b6-b9e3-3dfca2d5bfca",
    "assignerShortName": "mitre",
    "cveId": "CVE-2021-27137",
    "datePublished": "2026-07-16T00:00:00.000Z",
    "dateReserved": "2021-02-10T00:00:00.000Z",
    "dateUpdated": "2026-07-22T03:55:45.793Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Stored EPSS snapshot at this observation.

{
  "date": "2026-11-04",
  "epss": 0.03995,
  "percentile": 0.9055
}

Stored EPSS snapshot at this observation.

{
  "date": "2026-11-03",
  "epss": 0.03995,
  "percentile": 0.90533
}

Stored EPSS snapshot at this observation.

{
  "date": "2026-11-02",
  "epss": 0.03995,
  "percentile": 0.90521
}

Stored KEV snapshot at this observation.

{
  "cveID": "CVE-2021-27137",
  "cwes": [
    "CWE-121"
  ],
  "dateAdded": "2026-07-21",
  "dueDate": "2026-07-24",
  "forensicTriage": "Yes",
  "knownRansomwareCampaignUse": "Unknown",
  "notes": "This vulnerability affects a common open-source component, third-party library, proprietary implementation, or a protocol used by different products. Please check with specific vendors for information on patching status. For more information, please see: https://svn.dd-wrt.com/changeset/45724 ; BOD 26-04: https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk ; Forensics Triage Requirements: https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk ; https://nvd.nist.gov/vuln/detail/CVE-2021-27137",
  "product": "DD-WRT",
  "requiredAction": "Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.",
  "shortDescription": "DD-WRT contains a stack-based buffer overflow vulnerability that could allow an unauthenticated attacker to overflow an internal buffer used by UPnP and trigger a code execution vulnerability.",
  "vendorProject": "DD-WRT",
  "vulnerabilityName": "DD-WRT Stack-Based Buffer Overflow Vulnerability"
}