CVE-2021-20090
CISA KEVPublished November 3, 2021 · Updated April 3, 2026
high
Official Description+
Arcadyan Buffalo firmware contains a path traversal vulnerability that could allow unauthenticated, remote attackers to bypass authentication and access sensitive information. This vulnerability affects multiple routers across several different vendors.
Affected Products
| Vendor | Product |
|---|---|
| Arcadyan | Buffalo Firmware |
Patch Status
Patch by 2021-11-17
Recommended Actions
- Check if your systems use any of the affected products listed above.
- Apply vendor patches immediately if available.
- This vulnerability is in CISA's Known Exploited Vulnerabilities catalog — prioritize remediation.
- Monitor vendor advisories for updates and additional mitigations.
- Review logs for indicators of compromise related to CVE-2021-20090.