Description
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.
Scores
CVSS v4
1.7
EPSS
0.0015
EPSS Percentile
35.2%
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
CISA SSVC
Vulnrichment
Exploitation
none
Automatable
no
Technical Impact
partial
Details
CWE
CWE-770
CWE-799
Status
published
Products (3)
crates.io/letmeind
0 - 10.2.1crates.io
crates.io/letmeinfwd
0 - 10.2.1crates.io
mbuesch/letmein
< 10.2.1
Published
Jun 24, 2025
Tracked Since
Feb 18, 2026