CVE-2025-52570

CVE-2025-52570 affects the Letmein port-knock implementation. Before version 10.2.1, the connection limiter is implemented incorrectly, allowing an arbitrary number of simultaneous incoming connections (TCP, UDP, and Unix socket) for the services letmeind and letmeinfwd. The num-connections optio...

CVE-2025-52570 Letmein connection limiter allows an arbitrary amount of simultaneous connections

Letmein is an authenticating port knocker. Prior to version 10.2.1, The connection limiter is implemented incorrectly. It allows an arbitrary amount of simultaneously incoming connections TCP, UDP and Unix socket for the services letmeind and letmeinfwd. Therefore, the command line option...