CVE-2021-20716: Buffalo Bhr-4rv Firmware

Critical severity, CVSS 9.8. EPSS: 3.2% chance of exploitation in the next 30 days.

Hidden functionality in multiple Buffalo network devices (BHR-4RV firmware Ver.2.55 and prior, FS-G54 firmware Ver.2.04 and prior, WBR2-B11 firmware Ver.2.32 and prior, WBR2-G54 firmware Ver.2.32 and prior, WBR2-G54-KD firmware Ver.2.32 and prior, WBR-B11 firmware Ver.2.23 and prior, WBR-G54 firmware Ver.2.23 and prior, WBR-G54L firmware Ver.2.20 and prior, WHR2-A54G54 firmware Ver.2.25 and prior, WHR2-G54 firmware Ver.2.23 and prior, WHR2-G54V firmware Ver.2.55 and prior, WHR3-AG54 firmware Ver.2.23 and prior, WHR-G54 firmware Ver.2.16 and prior, WHR-G54-NF firmware Ver.2.10 and prior, WLA2-G54 firmware Ver.2.24 and prior, WLA2-G54C firmware Ver.2.24 and prior, WLA-B11 firmware Ver.2.20 and prior, WLA-G54 firmware Ver.2.20 and prior, WLA-G54C firmware Ver.2.20 and prior, WLAH-A54G54 firmware Ver.2.54 and prior, WLAH-AM54G54 firmware Ver.2.54 and prior, WLAH-G54 firmware Ver.2.54 and prior, WLI2-TX1-AG54 firmware Ver.2.53 and prior, WLI2-TX1-AMG54 firmware Ver.2.53 and prior, WLI2-TX1-G54 firmware Ver.2.20 and prior, WLI3-TX1-AMG54 firmware Ver.2.53 and prior, WLI3-TX1-G54 firmware Ver.2.53 and prior, WLI-T1-B11 firmware Ver.2.20 and prior, WLI-TX1-G54 firmware Ver.2.20 and prior, WVR-G54-NF firmware Ver.2.02 and prior, WZR-G108 firmware Ver.2.41 and prior, WZR-G54 firmware Ver.2.41 and prior, WZR-HP-G54 firmware Ver.2.41 and prior, WZR-RS-G54 firmware Ver.2.55 and prior, and WZR-RS-G54HP firmware Ver.2.55 and prior) allows a remote attacker to enable the debug option and to execute arbitrary code or OS commands, change the configuration, and cause a denial of service (DoS) condition.

Affected products

• Buffalo Bhr-4rv Firmware: up to and including 2.55
• Buffalo Fs-g54 Firmware: up to and including 2.04
• Buffalo Wbr-b11 Firmware: up to and including 2.23
• Buffalo Wbr-g54 Firmware: up to and including 2.23
• Buffalo Wbr-g54l Firmware: up to and including 2.20
• Buffalo WBR2-b11 Firmware: up to and including 2.32
• Buffalo WBR2-g54-Kd Firmware: up to and including 2.32
• Buffalo WBR2-g54 Firmware: up to and including 2.32
• Buffalo Whr-g54-Nf Firmware: up to and including 2.10
• Buffalo Whr-g54 Firmware: up to and including 2.16
• Buffalo WHR2-a54g54 Firmware: up to and including 2.25
• Buffalo WHR2-g54 Firmware: up to and including 2.23
• Buffalo WHR2-g54v Firmware: up to and including 2.55
• Buffalo WHR3-AG54 Firmware: up to and including 2.23
• Buffalo Wla-b11 Firmware: up to and including 2.20
• Buffalo Wla-g54 Firmware: up to and including 2.20
• Buffalo Wla-g54c Firmware: up to and including 2.20
• Buffalo WLA2-g54 Firmware: up to and including 2.24
• Buffalo WLA2-g54c Firmware: up to and including 2.24
• Buffalo Wlah-a54g54 Firmware: up to and including 2.54
• Buffalo Wlah-AM54G54 Firmware: up to and including 2.54
• Buffalo Wlah-g54 Firmware: up to and including 2.54
• Buffalo Wli-t1-b11 Firmware: up to and including 2.20
• Buffalo Wli-TX1-g54 Firmware: up to and including 2.20
• Buffalo WLI2-TX1-AG54 Firmware: up to and including 2.53
• and 10 more

Published 2021-04-28. Last modified 2026-06-17.