Auerswald COMfortel - Path Traversal (CVE-2021-40856)

CVE-2021-40856 is a vulnerability affecting Auerswald COMfortel IP devices, where improper path handling enables authentication bypass through certain crafted requests.

CrowdSec has been tracking this vulnerability and its exploits since 1st of June 2025.

Based on data from the CrowdSec network, nearly all observed exploitation of CVE-2021-40856 is fully opportunistic, with attackers indiscriminately scanning the entire internet. These attacks are automated and lack any form of target selection or reconnaissance. CrowdSec network telemetry also shows that exploitation of CVE-2021-40856 has significantly declined over the past week. Attack volumes are well below the long-term average, suggesting attackers are rapidly losing interest. The vulnerability appears to be falling out of active use across most threat landscapes.

Observed exploitation attempts typically target URLs containing /about/.. combined with specific request patterns.