{"uuid": "1b340c4a-eaac-42b6-993b-564939a9e72a", "vulnerability": {"vulnId": "CVE-2021-27137", "altId": []}, "gcve": {"origin_uuid": "405284c2-e461-4670-8979-7fd2c9755a60", "gna": 1, "object_uuid": "1b340c4a-eaac-42b6-993b-564939a9e72a"}, "status": {"exploited": true, "status_reason": "confirmed", "status_updated_at": "2026-07-21T00:00:00+00:00"}, "timestamps": {"asserted_at": "2026-07-21T00:00:00+00:00", "recorded_at": "2026-07-21T15:00:01+00:00", "first_seen_at": "2026-07-21T00:00:00+00:00"}, "scope": {"notes": "DD-WRT Stack-Based Buffer Overflow Vulnerability | Affected: DD-WRT / DD-WRT | 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. | Required action: Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA\u2019s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA\u2019s \u201cForensics Triage Requirements\u201d (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. | Due date: 2026-07-24 | Known ransomware campaign use (KEV): Unknown | Notes (KEV): 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"}, "evidence": [{"type": "vendor_report", "source": "cisa-kev", "signal": "successful_exploitation", "confidence": 0.8, "details": {"cwes": ["CWE-121"], "feed": "CISA Known Exploited Vulnerabilities Catalog", "product": "DD-WRT", "due_date": "2026-07-24", "date_added": "2026-07-21", "vendorProject": "DD-WRT", "vulnerabilityName": "DD-WRT Stack-Based Buffer Overflow Vulnerability", "knownRansomwareCampaignUse": "Unknown"}}], "references": [{"id": "CVE-2021-27137", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2021-27137"}]}