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TI-2025-32665 Aliases CVE-2025-52570GHSA-jpv7-p47h-f43j

Letmein connection limiter allows an arbitrary amount of simultaneous connections

Priority LOW 10CWE-770Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
Present
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · Low
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and GitHub. Impact type from CWE-770.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00376 31st percentileScored 2026-11-07
Fix Fixed letmein (mbuesch): 10.2.1letmeind (crates.io): 10.2.1+1 more product

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
mbueschletmeinbefore 10.2.110.2.1Patch availableCNA
—letmeind (crates.io)before 10.2.110.2.1Patch availableGHSA-jpv7-p47h-f43j
—letmeinfwd (crates.io)before 10.2.110.2.1Patch availableGHSA-jpv7-p47h-f43j
  • letmein Vendormbuesch Affected before 10.2.1 Fixed in 10.2.1 Patch available CNA
  • letmeind (crates.io) Vendor— Affected before 10.2.1 Fixed in 10.2.1 Patch available GHSA-jpv7-p47h-f43j
  • letmeinfwd (crates.io) Vendor— Affected before 10.2.1 Fixed in 10.2.1 Patch available GHSA-jpv7-p47h-f43j

Remediation

  • Fix · CNA letmein (mbuesch) Fixed in 10.2.1
  • Fix · GHSA-jpv7-p47h-f43j letmeind (crates.io) Fixed in 10.2.1 Advisory →
  • Fix · GHSA-jpv7-p47h-f43j letmeinfwd (crates.io) Fixed in 10.2.1 Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2025-52570
  2. 2026-10-03 Alias added: GHSA-jpv7-p47h-f43j

References

Advisory 1

Other 3

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences