GHSA-jpv7-p47h-f43j

Suggest an improvement
Source
https://github.com/advisories/GHSA-jpv7-p47h-f43j
Import Source
https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2025/06/GHSA-jpv7-p47h-f43j/GHSA-jpv7-p47h-f43j.json
JSON Data
https://api.osv.dev/v1/vulns/GHSA-jpv7-p47h-f43j
Aliases
Published
2025-06-23T21:24:59Z
Modified
2025-06-23T21:44:47.975928Z
Severity
  • 4.6 (Medium) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U CVSS Calculator
Summary
letmein connection limiter allows an arbitrary amount of simultaneous connections
Details

Impact

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.

letmeind is the public network facing daemon (TCP/UDP).

letmeinfwd is the internal firewall daemon that only listens on local Unix socket.

Possible Denial Of Service by resource exhaustion.

Affected versions

All versions <= 10.2.0 are affected.

Patches

All users shall upgrade to version 10.2.1.

Workarounds

Untested possible workarounds: - It might be possible to limit the number of active connections to the letmeind port (default 5800) via firewall. - The resource consumption of the service might be restricted with a service manager such as systemd.

Severity:

If a (D)DoS is run against the service, something is going to be affected. The connection limiter assures that the effect on the system itself is limited at the expense of the effect on the letmein services itself. So even with the connection limiter active, a (D)DoS can lead to a less responsive or unresponsive letmein service.

Database specific 
{
    "nvd_published_at": null,
    "cwe_ids": [
        "CWE-770"
    ],
    "severity": "MODERATE",
    "github_reviewed": true,
    "github_reviewed_at": "2025-06-23T21:24:59Z"
}
References

Affected packages

crates.io / letmeind

Package

Name
letmeind
View open source insights on deps.dev
Purl
pkg:cargo/letmeind

Affected ranges

Type
SEMVER
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
10.2.1

Database specific 

{
    "last_known_affected_version_range": "<= 10.2.0"
}

crates.io / letmeinfwd

Package

Name
letmeinfwd
View open source insights on deps.dev
Purl
pkg:cargo/letmeinfwd

Affected ranges

Type
SEMVER
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
10.2.1

Database specific 

{
    "last_known_affected_version_range": "<= 10.2.0"
}