CVE-2021-27137 DD-WRT CVE debrief

Who should care

Defenders and administrators of DD-WRT installations should assess exposure and apply mitigations according to vendor instructions. This includes reviewing system configurations, ensuring compliance with security policies, and verifying system integrity. Additionally, security teams and vulnerability management teams should prioritize patching or mitigating this vulnerability to prevent potential exploitation. The C

Why it matters

CVE-2021-27137 is a stack-based buffer overflow vulnerability in DD-WRT that is known to be exploited in the wild. Defenders and administrators of DD-WRT installations should assess exposure and apply mitigations according to vendor instructions. The vulnerability requires immediate attention due to the potential for code execution and disruption to services.

• Potential for code execution through exploitation of the buffer overflow vulnerability
• Need for immediate patching or mitigation to prevent exploitation
• Potential disruption to services if exploited
• Verification of system integrity and monitoring for suspicious activity

Technical summary

A stack-based buffer overflow vulnerability exists in DD-WRT, which is known to be exploited in the wild. The vulnerability requires immediate attention from defenders due to its potential for code execution and disruption to services. DD-WRT is a popular open-source firmware used in routers, and its exploitation could lead to unauthorized access and control of affected systems. The vulnerability is caused by a buffer overflow in the firmware's handling of certain inputs, allowing attackers to execute arbitrary code. Defenders should assess exposure and apply to

Defensive priority

High priority due to known exploitation

Recommended defensive actions

• Apply mitigations in accordance with vendor instructions
• Ensure compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk guidance
• Follow CISA’s Forensics Triage Requirements

Evidence notes

The vulnerability is described as a stack-based buffer overflow in DD-WRT. CISA has added this vulnerability to its Known Exploited Vulnerabilities catalog, indicating active exploitation.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.