TLS 1.3 denial via stale session version
Published Jan 21, 2024 · Updated May 30, 2025
Denial of service in Mbed TLS through 3.5.1 allows remote attackers to prevent TLS 1.3 connections after negotiating TLS 1.2. The mbedtls_ssl_session_reset routine leaves ssl->tls_version at the prior session's negotiated version instead of restoring the configured maximum. A server that reuses an SSL context with TLS 1.2 and TLS 1.3 enabled rejects later TLS 1.3 handshakes or forces clients to TLS 1.2.
Summary
What happened
Denial of service in Mbed TLS through 3.5.1 allows remote attackers to prevent TLS 1.3 connections after negotiating TLS 1.2. The mbedtls_ssl_session_reset routine leaves ssl->tls_version at the prior session's negotiated version instead of restoring the configured maximum. A server that reuses an SSL context with TLS 1.2 and TLS 1.3 enabled rejects later TLS 1.3 handshakes or forces clients to TLS 1.2.
The record
- CVE
- CVE-2023-52353
- Published
- Jan 21, 2024
- Updated
- May 30, 2025
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-384, T1499
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jan 21, 2024CVE publishedPublication date reported by the CVE source.
- May 30, 2025Record updatedLatest update available in the CVE record.
Exploitability
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What is affected?
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Published CVSS scores
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Attacks
What attackers are doing with it
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Public exploit references
- TLS 1.2 to TLS 1.3 session-reset reproductionproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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