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.
https://www.tenable.com/security/research/tra-2021-13
https://www.secpod.com/blog/arcadyan-based-routers-and-modems-under-active-exploitation/