Unauthenticated service interruption via blocking TLS handshake
Published Jul 24, 2023 · Updated Nov 20, 2025
Denial of service in the Keylime registrar in Red Hat Enterprise Linux 9 allows remote attackers to block clients through its TLS port. RegistrarServer wraps its listening socket with a blocking TLS handshake, so one connection that remains open prevents the server loop from accepting or serving other clients. No authentication is required to hold the connection open; agents and tenants lose registrar access, while the verifier is not affected.
Summary
What happened
Denial of service in the Keylime registrar in Red Hat Enterprise Linux 9 allows remote attackers to block clients through its TLS port. RegistrarServer wraps its listening socket with a blocking TLS handshake, so one connection that remains open prevents the server loop from accepting or serving other clients. No authentication is required to hold the connection open; agents and tenants lose registrar access, while the verifier is not affected.
The record
- CVE
- CVE-2023-38200
- Published
- Jul 24, 2023
- Updated
- Nov 20, 2025
- Vendor
- Red Hat
- Product
- Red Hat Enterprise Linux 9
- Classifications
- CWE-834, T1499.002
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jul 24, 2023CVE publishedPublication date reported by the CVE source.
- Nov 20, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Public exploit references
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Technologies
Your stack
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Your stack
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