CVE-2021-27137: DD-WRT Stack-Based Buffer Overflow Vulnerability

DD-WRT DD-WRT · in CISA KEV since 2026-07-21

What it is

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 (CISA)

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.

Original records: NVD · CISA KEV · JSON: /api/cve/CVE-2021-27137.json · all KEV CVEs