Is CVE-2023-42116 actively exploited?

CVE-2023-42116 has no public evidence of in-the-wild exploitation as of 2025-11-04.

What is the CVSS score for CVE-2023-42116?

CVE-2023-42116 has a CVSS score of 9.8 (CRITICAL severity). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

How do I patch CVE-2023-42116?

Patch guidance is available from exim security advisories. CVEDatabase generates AI-assisted remediation guidance on demand for CVE-2023-42116.

Fix CVE-2023-42116 - CRITICAL exim exim

Description

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 Metrics

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack Vector: network
Complexity: low
Privileges: none
User Action: none
Scope: unchanged
Confidentiality: high
Integrity: high
Availability: high
Weaknesses: CWE-121

Metadata

Primary Vendor: EXIM
Published: 5/3/2024
Last Modified: 11/4/2025
Source: NIST NVD
Note: Verify all details with official vendor sources before applying patches.

CVE-2023-42116

Description

CVSS Metrics

Metadata

Affected Products

Remediation Guidance

Executive Summary