Is CVE-2023-42117 in the CISA KEV catalog?

No. CVE-2023-42117 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2023-42117?

CVE-2023-42117 has a CVSS v3 base score of 9.8 (CRITICAL).

What is the EPSS score for CVE-2023-42117?

CVE-2023-42117 has an EPSS score of 5.67% (92th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2023-42117?

Upgrade exim4 on debian 11 to 4.94.2-7+deb11u4 or later. Fixes are available for 4 affected products.

CVE & CISA-KEV Catalog

CVE-2023-42117

CRITICALEPSS 92th pctl

9.8

CVSS v3

NVD

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.

CWE-138

How to fix

Remediation Available

exim4Debian

Fixed in:4.94.2-7+deb11u4CVE-2023-42117

Fixed in:4.96-15+deb12u3CVE-2023-42117

Fixed in:4.97~RC2-2CVE-2023-42117

exim4Ubuntu

Fixed in:4.82-3ubuntu2.4+esm7USN-6455-1

Fixed in:4.86.2-2ubuntu2.6+esm5USN-6455-1

Fixed in:4.90.1-1ubuntu1.10+esm2USN-6455-1

Fixed in:4.93-13ubuntu1.9USN-6455-1

Fixed in:4.95-4ubuntu2.4USN-6455-1

Fixed in:4.96-14ubuntu1.3USN-6455-1

Fixed in:4.96-17ubuntu2.1USN-6455-1

exim4-daemon-heavyUbuntu

Fixed in:4.82-3ubuntu2.4+esm7USN-6455-1

Fixed in:4.86.2-2ubuntu2.6+esm5USN-6455-1

Fixed in:4.90.1-1ubuntu1.10+esm2USN-6455-1

Fixed in:4.93-13ubuntu1.9USN-6455-1

Fixed in:4.95-4ubuntu2.4USN-6455-1

Fixed in:4.96-14ubuntu1.3USN-6455-1

Fixed in:4.96-17ubuntu2.1USN-6455-1

exim4-daemon-lightUbuntu

Fixed in:4.82-3ubuntu2.4+esm7USN-6455-1

Fixed in:4.86.2-2ubuntu2.6+esm5USN-6455-1

Fixed in:4.90.1-1ubuntu1.10+esm2USN-6455-1

Fixed in:4.93-13ubuntu1.9USN-6455-1

Fixed in:4.95-4ubuntu2.4USN-6455-1

Fixed in:4.96-14ubuntu1.3USN-6455-1

Fixed in:4.96-17ubuntu2.1USN-6455-1

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

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

Exploit Intelligence

5.67%probability of exploitation in 30 days

92ndpercentile

High risk: more likely to be exploited than 92% of all known CVEs.

References

Third-Party Advisory1

zerodayinitiative.com

Other references1

lists.debian.org

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2025-11-03.