Authentication bypass via uninitialized Finished message
Published Mar 25, 2025 · Updated Mar 25, 2025
Use of uninitialized memory in Mbed TLS before 2.28.10 and 3.x before 3.6.3 allows remote attackers to bypass TLS authentication. The TLS 1.2 Finished-message calculation continues after a memory-allocation or cryptographic-driver error and uses uninitialized stack bytes as its result. Exploitation requires an attacker to induce one of those failures during the handshake, enabling transcript tampering or replay-based peer impersonation.
Summary
What happened
Use of uninitialized memory in Mbed TLS before 2.28.10 and 3.x before 3.6.3 allows remote attackers to bypass TLS authentication. The TLS 1.2 Finished-message calculation continues after a memory-allocation or cryptographic-driver error and uses uninitialized stack bytes as its result. Exploitation requires an attacker to induce one of those failures during the handshake, enabling transcript tampering or replay-based peer impersonation.
The record
- CVE
- CVE-2025-27810
- Published
- Mar 25, 2025
- Updated
- Mar 25, 2025
- Vendor
- TrustedFirmware.org
- Product
- Mbed TLS
- Classifications
- CWE-908, T1557
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Mar 25, 2025CVE publishedPublication date reported by the CVE source.
- Mar 25, 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?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <2.28.10
- Affected versionversion=3.0.0 <3.6.3
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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