CVE-2023-42118
Exim libspf2 Integer Underflow Remote Code Execution Vulnerability
Description
Exim libspf2 Integer Underflow Remote Code Execution Vulnerability. This vulnerability allows network-adjacent attackers to execute arbitrary code on affected installations of Exim libspf2. Authentication is not required to exploit this vulnerability. The specific flaw exists within the parsing of SPF macros. When parsing SPF macros, the process does not properly validate user-supplied data, which can result in an integer underflow before writing to memory. An attacker can leverage this vulnerability to execute code in the context of the service account. . Was ZDI-CAN-17578.
INFO
Published Date :
May 3, 2024, 3:15 a.m.
Last Modified :
Aug. 7, 2025, 6:17 p.m.
Remotely Exploit :
No
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.0 | HIGH | [email protected] | ||||
| CVSS 3.1 | HIGH | [email protected] |
Solution
- Update the affected libspf2 package.
- If no update is available, monitor for updates.
Public PoC/Exploit Available at Github
CVE-2023-42118 has a 2 public
PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2023-42118.
| URL | Resource |
|---|---|
| https://www.zerodayinitiative.com/advisories/ZDI-23-1472/ | Third Party Advisory |
| http://www.openwall.com/lists/oss-security/2025/03/28/1 | Mailing List |
| https://www.zerodayinitiative.com/advisories/ZDI-23-1472/ | Third Party Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2023-42118 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2023-42118
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
This project focused on simulating real-world vulnerability assessment tasks using enterprise-grade scanners and manual enumeration tools. Performing full scans on simulated Linux environments to identify known vulnerabilities and weak configurations using CVE databases (via MITRE), and produced structured risk reports with recommenation.
Exim SMTP Vulnerabilities list
cve exim vulnerabilities
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2023-42118 vulnerability anywhere in the article.
-
Daily CyberSecurity
Windows 11 Now Runs on iPad in EU via UTM Virtual Machine
Running Windows 11 on an iPad via a virtual machine has long been a formidable challenge, primarily due to Apple’s restrictions on iPadOS, which prohibit the execution of a full Just-In-Time (JIT) com ... Read more
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Cybersecurity News
Exim Mail Transfer Agent Vulnerable to Remote SQL Injection (CVE-2025-26794), PoC Published
A new vulnerability has been discovered in Exim, a widely used mail transfer agent (MTA) for Unix-like systems. The vulnerability, tracked as CVE-2025-26794 and assigned a CVSS score of 7.5, could all ... Read more
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Cybersecurity News
13,000 MikroTik Routers Hijacked for Global Malspam Operation
A recent report from Infoblox Threat Intel highlights a sophisticated botnet operation leveraging a simple DNS misconfiguration to distribute malware on a massive scale. This botnet, built on approxim ... Read more
-
TheCyberThrone
Sophos fixes Triple Critical Vulnerabilities in its Firewall
Sophos released patches for three critical security vulnerabilities in their widely-used network security tool, Sophos Firewall that posed significant risks, including remote code execution and privil ... Read more
The following table lists the changes that have been made to the
CVE-2023-42118 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Aug. 07, 2025
Action Type Old Value New Value Added CVSS V3.1 AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Added CPE Configuration AND OR *cpe:2.3:a:libspf2_project:libspf2:-:*:*:*:*:*:*:* OR cpe:2.3:a:exim:exim:-:*:*:*:*:*:*:* Added Reference Type CVE: http://www.openwall.com/lists/oss-security/2025/03/28/1 Types: Mailing List Added Reference Type CVE: https://www.zerodayinitiative.com/advisories/ZDI-23-1472/ Types: Third Party Advisory Added Reference Type Zero Day Initiative: https://www.zerodayinitiative.com/advisories/ZDI-23-1472/ Types: Third Party Advisory -
CVE Modified by af854a3a-2127-422b-91ae-364da2661108
Mar. 28, 2025
Action Type Old Value New Value Added Reference http://www.openwall.com/lists/oss-security/2025/03/28/1 -
CVE Modified by af854a3a-2127-422b-91ae-364da2661108
Nov. 21, 2024
Action Type Old Value New Value Added Reference https://www.zerodayinitiative.com/advisories/ZDI-23-1472/ -
CVE Modified by [email protected]
Sep. 18, 2024
Action Type Old Value New Value Changed Description Exim libspf2 Integer Underflow Remote Code Execution Vulnerability. This vulnerability allows network-adjacent attackers to execute arbitrary code on affected installations of Exim libspf2. Authentication is not required to exploit this vulnerability. The specific flaw exists within the parsing of SPF macros. When parsing SPF macros, the process does not properly validate user-supplied data, which can result in an integer underflow before writing to memory. An attacker can leverage this vulnerability to execute code in the context of the service account. Was ZDI-CAN-17578. Exim libspf2 Integer Underflow Remote Code Execution Vulnerability. This vulnerability allows network-adjacent attackers to execute arbitrary code on affected installations of Exim libspf2. Authentication is not required to exploit this vulnerability. The specific flaw exists within the parsing of SPF macros. When parsing SPF macros, the process does not properly validate user-supplied data, which can result in an integer underflow before writing to memory. An attacker can leverage this vulnerability to execute code in the context of the service account. . Was ZDI-CAN-17578. -
CVE Modified by [email protected]
May. 14, 2024
Action Type Old Value New Value -
CVE Received by [email protected]
May. 03, 2024
Action Type Old Value New Value Added Description Exim libspf2 Integer Underflow Remote Code Execution Vulnerability. This vulnerability allows network-adjacent attackers to execute arbitrary code on affected installations of Exim libspf2. Authentication is not required to exploit this vulnerability. The specific flaw exists within the parsing of SPF macros. When parsing SPF macros, the process does not properly validate user-supplied data, which can result in an integer underflow before writing to memory. An attacker can leverage this vulnerability to execute code in the context of the service account. Was ZDI-CAN-17578. Added Reference Zero Day Initiative https://www.zerodayinitiative.com/advisories/ZDI-23-1472/ [No types assigned] Added CWE Zero Day Initiative CWE-191 Added CVSS V3 Zero Day Initiative AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H