# CVE-2021-27137: A DD-WRT bug is being used in attacks

Status: Being used now (CISA KEV, added 2026-07-21)
Who: 
Do this: 

## Agent prompt (read-only)
Read-only check, change nothing, send nothing anywhere.
Is DD-WRT DD-WRT (CVE-2021-27137) installed or running on this machine or in this project?
1. Find every copy and its version (apps, packages, containers, lockfiles).
2. Compare each version against the vendor's fixed version for CVE-2021-27137. Quote the vendor page you used.
3. Report a table: where, version, fixed version, status (exposed / fixed / not installed / unsure).
4. List the exact update steps, but do not run them.

## Official 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.

## Sources
- https://nvd.nist.gov/vuln/detail/CVE-2021-27137
- https://nvd.nist.gov/vuln/detail/CVE-2021-27137

Generated by isitexploited.org from public sources. Verify version numbers against the vendor before acting.