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High

Keylime's registrar vulnerable to Denial-of-service attack via a single open connection

  • Disclosed: 01.08.2023
  • Updated: 11.10.2026 13:18

Impact

Keylime registrar is prone to a simple denial of service attack in which an adversary opens a connection to the TLS port (by default, port 8891) blocking further, legitimate connections. As long as the connection is open, the registrar is blocked and cannot serve any further clients (agents and tenants), which prevents normal operation. The problem does not affect the verifier.

Patches

Users should upgrade to release 7.4.0

Affected software

Click a technology to see all vulnerabilities affecting it.

PlatformPackageVulnerable versionsFixed in
Python (PyPI) keylime < 7.4.0 7.4.0

References

CVSS score 7.5/10
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness (CWE)
CWE-834
Platform
Python (PyPI)
Package
keylime
Disclosed
01.08.2023
Updated
11.10.2026 13:18

Sources and licenses

OSV / GitHub Advisory Database - PYSEC-2026-1489 - PyPA Advisory Database; CC BY 4.0

OSV / GitHub Advisory Database - GHSA-pg75-v6fp-8q59 - CC BY 4.0

Vulnerability history: keylime

All published vulnerabilities of this package (Python (PyPI)), newest first. Shows whether this is a one-off slip or a package that needs watching.

All (9) in the archive
Total entries
9
First → latest
05.2022 05.2026
Without a fix
1
Exploited in attacks
0

Severity breakdown

  • Critical 2
  • High 4
  • Medium 2
  • Low 1

Disclosures per year

Severity:
  1. A flaw was found in Keylime. The Keylime registrar, since version 7.12.0, does not enforce client-side Transport Layer Security (TLS) authentication. This authentication bypass vulnerability allows un
    Critical · 9.8 CVE-2026-1709 < 7.12.0 7.12.0
  2. A vulnerability has been identified in keylime where an attacker can exploit this flaw by registering a new agent using a different Trusted Platform Module (TPM) device but claiming an existing agent'
    High · 8.2 CVE-2025-13609 not given by the source no fix
  3. Keylime registrar and (untrusted) Agent can be bypassed by an attacker
    High · 6.5 CVE-2023-38201 < 7.5.0 7.5.0
  4. Keylime's registrar vulnerable to Denial-of-service attack via a single open connection this entry
    High · 7.5 CVE-2023-38200 < 7.4.0 7.4.0
  5. A vulnerability was found in keylime. This security issue happens in some circumstances, due to some improperly handled exceptions, there exists the possibility that a rogue agent could create errors
    High · 5.1 CVE-2022-3500 < 6.5.1 6.5.1
  6. Tenant and Verifier might not use the same registrar data
    Critical · 9.1 CVE-2022-1053 < 6.4.0 6.4.0

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