Vulnerability record · CVE-2023-42117 · published 3 May 2024

CVE-2023-42117: Exim vulnerability

Exim · Exim

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.

9.8 CVSS 3.1 Critical EPSS 5.7% · top 7.2% CWE-138 · CWE-138

9.8CVSS 3.1 base score

5.7%EPSS exploitation probability, 30 days

NoNot in CISA KEV

1Affected product versions listed by NVD

3References

17 Jun 2026Last modified by NVD

Description

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

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

Exim Exim

References

Link	Tags
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

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

9.8CVE-2019-16928Exim heap buffer overflow in string_vformat via long EHLO commandExim 4.92 through 4.92.2 contains a heap-based buffer overflow in string_vformat in string.c triggered by a long EHLO command, allowing remote code e…KEVEPSS 42%analysed27 Sep 2019 9.8CVE-2019-10149Exim MTA improper recipient validation leads to remote command executionExim versions 4.87 through 4.91 fail to properly validate recipient addresses in the deliver_message() function in /src/deliver.c, allowing command i…KEVEPSS 100%analysed5 Jun 2019 9.8CVE-2018-6789Exim SMTP base64d buffer overflow allows remote code executionExim before 4.90.1 contains a buffer overflow in the base64d function of its SMTP listener. A handcrafted message can trigger the overflow, and the f…KEVEPSS 82%analysed8 Feb 2018 9.8CVE-2010-4344Exim SMTP heap buffer overflow enables remote code executionExim before 4.70 has a heap-based buffer overflow in string_vformat in string.c. A remote SMTP session that sends two MAIL commands plus a large mess…KEVEPSS 72%analysed14 Dec 2010 7.8CVE-2010-4345Exim local privilege escalation via alternate config file command injectionExim 4.72 and earlier lets the exim user account specify an alternate configuration file whose directives can contain arbitrary commands, as shown wi…KEVEPSS 18%analysed14 Dec 2010 9.8CVE-2026-45185Exim use after free vulnerabilityExim before 4.99.3, in certain GnuTLS configurations, has a remotely reachable use-after-free in the BDAT body parsing path. It is triggered when a c…EPSS 0.94%12 May 2026 9.8CVE-2026-40685Exim out-of-bounds write vulnerabilityIn Exim before 4.99.2, when JSON lookup is enabled, an out-of-bounds heap write can occur when a JSON operator encounters malformed JSON in an untrus…EPSS 0.58%30 Apr 2026 9.8CVE-2025-67896Exim heap-based buffer overflow vulnerabilityExim before 4.99.1, with certain non-default rate-limit configurations, allows a remote heap-based buffer overflow because database records are cast …EPSS 0.47%14 Dec 2025

Source: NIST National Vulnerability Database (record CVE-2023-42117), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.