CVE-2023-42117

Name: CVE-2023-42117
Creator: NVD / NIST
Published: 2024-05-03T03:15:50.463+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10EPSS 5.67%

Last modified Jun 17, 2026

CVE-2023-42117 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. Exim Improper Neutralization of Special Elements Remote Code Execution Vulnerability. This vulnerability allows remote attackers to execute arbitrary code on affected installations of Exim. EPSS estimates a 5.67% chance of exploitation in the next 30 days.

Description

Exim Improper Neutralization of Special Elements 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 smtp service, which listens on TCP port 25 by default. The issue results from the lack of proper validation of user-supplied data, which can result in a memory corruption condition. An attacker can leverage this vulnerability to execute code in the context of the current process. Was ZDI-CAN-17554.

Metrics

CVSS 3.1

9.8/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

5.67%

92.0th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-138

Affected Software

Vendor	Product	Versions
Exim	Exim	< 4.96.2

References

https://www.zerodayinitiative.com/advisories/ZDI-23-1471/Third Party Advisory
https://lists.debian.org/debian-lts-announce/2024/10/msg00029.html
https://www.zerodayinitiative.com/advisories/ZDI-23-1471/Third Party Advisory

Timeline

Published: May 3, 2024
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2023-42117?

How severe is CVE-2023-42117?

CVE-2023-42117 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 5.67% probability of exploitation in the next 30 days.

How do I fix CVE-2023-42117?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2023-42117?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST