CVE-2025-52570 LOW

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

Vendor Mbuesch
Product letmein
Weakness CWE-799
Published June 24, 2025
Last update June 24, 2025
View on NVD All CVEs

CVSS base score

1.7/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality —
Integrity —

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U

What the vulnerability does

01Description

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 num-connections is not effective and does not limit the number of simultaneously incoming connections. This issue has been patched in version 10.2.1.

Key dates

02Disclosure timeline

June 24, 2025 CVE published
June 24, 2025 Record updated