CVE-2023-42116

Exim SMTP Challenge Stack-based Buffer Overflow Remote Code Execution Vulnerability. This vulnerability allows remote attackers to execute arbitrary code 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 the length of user-supplied data prior to copying it to a fixed-length stack-based buffer. An attacker can leverage this vulnerability to execute code in the context of the service account. . Was ZDI-CAN-17515.

CVSS v3 9.8 CRITICAL

9.8^/10

CVSS v3 : CRITICAL

Vector :

Exploitability : 3.9 / Impact : 5.9

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://www.zerodayinitiative.com/advisories/ZDI-23-1470/	Third Party Advisory
https://www.zerodayinitiative.com/advisories/ZDI-23-1470/	Third Party Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:exim:exim:*:*:*:*:*:*:*:*

History

07 Aug 2025, 18:05

Type	Values Removed	Values Added
References	~~() https://www.zerodayinitiative.com/advisories/ZDI-23-1470/ -~~	() https://www.zerodayinitiative.com/advisories/ZDI-23-1470/ - Third Party Advisory
First Time		Exim exim Exim
CVSS	v2 : ~~unknown~~ v3 : ~~8.1~~	v2 : unknown v3 : 9.8
CPE		cpe:2.3:a:exim:exim::::::::

Information

Published : 2024-05-03 03:15

Updated : 2025-08-07 18:05

NVD link : CVE-2023-42116

Mitre link : CVE-2023-42116

CVE.ORG link : CVE-2023-42116

JSON object : View

Products Affected

exim

exim

CWE

CWE-121

Stack-based Buffer Overflow

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