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Fencer Vulns
high 8.1

CVE-2023-42117 json

Exim Improper Neutralization of Special Elements Remote Code Execution Vulnerability

published 2024-05-03 2 y ago modified 2026-06-17 4 mo ago also EUVD-2023-46576

cvss
8.1
version 3.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
6.7%
EPSS 6.7% chance of exploitation in 30 days, percentile 93%
public exploits
0
none known

Summary

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.

Patch / fix

  • exim exim 4.96.2
  • university_of_cambridge exim 4.96.2
  • exim4 Debian 12 4.96-15+deb12u3
  • exim4 Debian 14, Debian 13 4.97~RC2-2

debian advisories DEBIAN-CVE-2023-42117

  • exim4 Ubuntu 20.04 LTS 4.93-13ubuntu1.9
  • exim4 Ubuntu 22.04 LTS 4.95-4ubuntu2.4
  • exim4 Ubuntu Pro 14.04 LTS 4.82-3ubuntu2.4+esm7
  • exim4 Ubuntu Pro 16.04 LTS 4.86.2-2ubuntu2.6+esm5
  • exim4 Ubuntu Pro 18.04 LTS 4.90.1-1ubuntu1.10+esm2

ubuntu advisories UBUNTU-CVE-2023-42117

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • exim openSUSE Tumbleweed 4.96.2-1.1
  • exim Package Hub 15 SP5, openSUSE Leap 15.5 4.97.1-bp155.5.9.1
  • exim Package Hub 15 SP4, openSUSE Leap 15.4 4.94.2-bp154.2.9.1
  • exim Package Hub 15 SP5, openSUSE Leap 15.5 4.94.2-bp155.5.6.1

opensuse advisories openSUSE-SU-2024:13333-1openSUSE-SU-2024:0007-1openSUSE-SU-2023:0304-1openSUSE-SU-2023:0303-1

  • exim Alpine 3.24, Alpine 3.23, Alpine 3.22 +5 more 4.96.2-r0

alpine advisories ALPINE-CVE-2023-42117

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2023-42117 updated cvss 8.1

Exim: Improper Neutralization of Special Elements Remote Code Execution Vulnerability

  • Red Hat All currently supported Red Hat products
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
2 y ago

Exploit prediction

6.73% chance of exploitation in the next 30 days, higher than 93% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.0 8.1 CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

  • Exim Exim

Classification

Weakness
  • CWE-138 Improper Neutralization of Special Elements

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.