cve-2021-27137

{
  "cvss": 8.1,
  "datePublished": "2026-07-21",
  "dateUpdated": "2026-07-21",
  "description": "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.",
  "dueDate": "2026-07-24",
  "id": "CVE-2021-27137",
  "kev_catalogs": [
    "cisa"
  ],
  "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.",
  "severity": "HIGH",
  "source": "cisa_known_exploited",
  "title": "DD-WRT Stack-Based Buffer Overflow Vulnerability",
  "vendor": "DD-WRT"
}