Out-of-bounds read in Exim
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Information disclosure
- Confidentiality · integrity · availability
- Low · None · None
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-125 and the CVSS impact.
Summary
Exim NTLM Challenge Out-Of-Bounds Read Information Disclosure Vulnerability. This vulnerability allows remote attackers to disclose sensitive information on affected installations of Exim. Authentication is not required to exploit this vulnerability. The specific flaw exists within the handling of NTLM challenge requests. The issue results from the lack of proper validation of user-supplied data, which can result in a read past the end of an allocated data structure. An attacker can leverage this vulnerability to disclose information in the context of the service account. . Was ZDI-CAN-17433.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
No fixed version listed by the sources yet.
Vendor assessments
Timeline
- 2026-10-02 Threatist record created from CVE-2023-42114
- 2026-10-03 Alias added: GHSA-h5j4-2q8w-q3q4
References
Advisory 1
More Exim vulnerabilities
- TI-2019-12627 Exim 4.92 through 4.92.2 allows remote code execution, a different vulnerability than… KEVCVSS 3.1CRITICAL 9.8
- TI-2019-07471 OS command injection in exim KEVCVSS 3.1CRITICAL 9.8
- TI-2018-04965 An issue was discovered in the base64d function in the SMTP listener in Exim before… KEVCVSS 3.1CRITICAL 9.8
- TI-2010-04077 Heap-based buffer overflow in the string_vformat function in string.c in Exim before 4.70… KEVCVSS 3.1CRITICAL 9.8
- TI-2010-04078 Exim 4.72 and earlier allows local users to gain privileges by leveraging the ability of… KEVCVSS 3.1HIGH 7.8
- TI-2025-19707 SQL injection in Exim CVSS 3.1CRITICAL 9.8
Sources
- CVE-2023-42114 · CVE Program
- CVE-2023-42114 · NVD
- FIRST EPSS
- GHSA-h5j4-2q8w-q3q4 · GitHub Advisory Database · CC BY 4.0
- CVE-2023-42114 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences