CVE-2021-40859: Auerswald Compact 5500r Firmware

Critical severity, CVSS 9.8. EPSS: 72% chance of exploitation in the next 30 days.

Backdoors were discovered in Auerswald COMpact 5500R 7.8A and 8.0B devices, that allow attackers with access to the web based management application full administrative access to the device.

Affected products

• Auerswald Compact 5500r Firmware: version 7.8a only; version 8.0b only

Published 2021-12-07. Last modified 2026-06-17.