Arcadyan Buffalo Firmware Path Traversal Vulnerability

[ Why it matters ]Priority signals

• Exploited in the wild: on CISA's Known Exploited Vulnerabilities list since 2021-11-03
• EPSS: 100% chance of exploitation in the next 30 days (higher than 100% of CVEs)
• Critical severity: CVSS 9.8

[ Description ]Official description

A path traversal vulnerability in the web interfaces of Buffalo WSR-2533DHPL2 firmware version <= 1.02 and WSR-2533DHP3 firmware version <= 1.24 could allow unauthenticated remote attackers to bypass authentication.

CISA: 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.

[ Fixes ]Fixes and patches

CISA required action (US federal deadline 17 Nov 2021): Apply updates per vendor instructions.

No fix or interim patch is linked from our sources yet. Check the vendor references below and limit exposure of affected systems until a fix is available.

[ References ]References

• www.kb.cert.org/vuls/id/914124Third Party AdvisoryUS Government Resource
• www.secpod.com/blog/arcadyan-based-routers-and-modems-under-active-exploitationExploitThird Party Advisory
• www.tenable.com/security/research/tra-2021-13ExploitThird Party Advisory
• www.cisa.gov/known-exploited-vulnerabilities-catalogUS Government Resource