CVE-2023-42118 — HIGH (8.8)

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.

CVSS Score

8.8

HIGH

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

Attack Vector

ADJACENT_NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

NONE

Scope

UNCHANGED

Confidentiality

HIGH

Integrity

HIGH

Availability

HIGH

Affected Products

Vendor	Product	Versions
Libspf2 Project	Libspf2	-
Exim	Exim	-

Related Weaknesses (CWE)

CWE-191

References

https://www.zerodayinitiative.com/advisories/ZDI-23-1472/Third Party Advisory
http://www.openwall.com/lists/oss-security/2025/03/28/1Mailing List
https://www.zerodayinitiative.com/advisories/ZDI-23-1472/Third Party Advisory

FAQ

What is CVE-2023-42118?

CVE-2023-42118 is a vulnerability with a CVSS score of 8.8 (HIGH). Exim libspf2 Integer Underflow Remote Code Execution Vulnerability. This vulnerability allows network-adjacent attackers to execute arbitrary code on affected installations of Exim libspf2. Authentica...

How severe is CVE-2023-42118?

CVE-2023-42118 has been rated HIGH with a CVSS base score of 8.8/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2023-42118?

Check the references section above for vendor advisories and patch information. Affected products include: Libspf2 Project Libspf2, Exim Exim.