Arcadyan Buffalo Firmware Path Traversal Vulnerability

Added to KEV
2021-11-03
Federal due date
2021-11-17
Vendor
Arcadyan
Product
Buffalo Firmware
EPSS
100.0th percentile (score 0.944, as of 2026-06-08)
NVD CVSS v3.1
Ransomware use
Unknown
Upstream
https://nvd.nist.gov/vuln/detail/CVE-2021-20090

CISA short 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.

Required action

Apply updates per vendor instructions.

EPSS percentile is the FIRST.org exploit-probability ranking as of the date noted above; it moves daily. CVSS reflects NVD's analysis at time of publication.