Process crash via overflowing extension length
Published Jan 31, 2024 · Updated Nov 4, 2025
Integer overflow in Mbed TLS 2.x before 2.28.7 and 3.x before 3.5.2 allows attackers to crash processes that write X.509 extensions. The mbedtls_x509_set_extension function increments an unchecked SIZE_MAX value length to zero, allocates no backing buffer, then copies the extension through a null pointer. Reachability requires attacker influence over the library call's extension-length argument; the demonstrated consequence is a process segfault and service interruption.
Summary
What happened
Integer overflow in Mbed TLS 2.x before 2.28.7 and 3.x before 3.5.2 allows attackers to crash processes that write X.509 extensions. The mbedtls_x509_set_extension function increments an unchecked SIZE_MAX value length to zero, allocates no backing buffer, then copies the extension through a null pointer. Reachability requires attacker influence over the library call's extension-length argument; the demonstrated consequence is a process segfault and service interruption.
The record
- CVE
- CVE-2024-23775
- Published
- Jan 31, 2024
- Updated
- Nov 4, 2025
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-190, T1499.004
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jan 31, 2024CVE publishedPublication date reported by the CVE source.
- Nov 4, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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What is affected?
Affected products and versions are unavailable in this record.
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.
Weakness, pattern, technique
Public exploit references
- mbedtls_x509_set_extension SIZE_MAX reproducerproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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