CVE-2021-40856: Auerswald Comfortel 1400 IP Firmware

High severity, CVSS 7.5. EPSS: 50.1% chance of exploitation in the next 30 days.

Auerswald COMfortel 1400 IP and 2600 IP before 2.8G devices allow Authentication Bypass via the /about/../ substring.

Affected products

• Auerswald Comfortel 1400 IP Firmware: up to and including 2.8f
• Auerswald Comfortel 2600 IP Firmware: up to and including 2.8f
• Auerswald Comfortel 3600 IP Firmware: up to and including 2.8f

Published 2021-12-13. Last modified 2026-06-17.