CVE-2021-20090: Arcadyan Buffalo Firmware Path Traversal Vulnerability

Critical severity, CVSS 9.8. Actively exploited: in CISA KEV since 2021-11-03. EPSS: 100% chance of exploitation in the next 30 days.

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.

Affected products

• Buffalo Wsr-2533dhp3-Bk Firmware: up to and including 1.24
• Buffalo Wsr-2533dhpl2-Bk Firmware: up to and including 1.02

Published 2021-04-29. Last modified 2026-06-17.