Information disclosure via unvalidated NTLM challenge offset
Published May 3, 2024 · Updated Nov 4, 2025
Out-of-bounds read in Exim before 4.96.1 allows remote attackers to disclose service-process memory through an NTLM challenge. The SPA authenticator trusts an attacker-controlled offset in the challenge and reads beyond the end of its allocated data structure. Exploitation requires SPA/NTLM authentication to be enabled but requires no account, and disclosed memory is limited to the Exim service context.
Summary
What happened
Out-of-bounds read in Exim before 4.96.1 allows remote attackers to disclose service-process memory through an NTLM challenge. The SPA authenticator trusts an attacker-controlled offset in the challenge and reads beyond the end of its allocated data structure. Exploitation requires SPA/NTLM authentication to be enabled but requires no account, and disclosed memory is limited to the Exim service context.
The record
- CVE
- CVE-2023-42114
- Published
- May 3, 2024
- Updated
- Nov 4, 2025
- Vendor
- LibSPF2 Project
- Product
- Exim
- Classifications
- CWE-125, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- May 3, 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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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <4.96.1
- Affected versionversion=0 <4.97
- Affected versionversion=exim 4.95
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
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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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