Summary
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.
Remediation
CISA required actionApply 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.
References
- Advisoryhttps://svn.dd-wrt.com/changeset/45724
- Advisoryhttps://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk
- Advisoryhttps://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk
- Advisoryhttps://nvd.nist.gov/vuln/detail/CVE-2021-27137
- Referencehttps://ssd-disclosure.com/ssd-advisory-dd-wrt-upnp-buffer-overflow/
- Referencehttps://securityaffairs.com/193290/uncategorized/iot-botnet-c0xmo-adds-competitor-killing-capability.html
- Referencehttps://www.bleepingcomputer.com/news/security/c0xmo-botnet-spreads-via-dd-wrt-router-flaw-kills-rival-malware/
- Referencehttps://www.fortinet.com/blog/threat-research/inside-cross-platform-propagation-of-new-gafgyt-variant-c0xmo
- Referencehttps://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-27137