CVE-2023-42115

Publication date 28 September 2023

Last updated 30 May 2025

Ubuntu priority

Medium

Why this priority?

Cvss 3 Severity Score

9.8 · Critical

Score breakdown

Exim AUTH Out-Of-Bounds Write 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 write past the end of a buffer. An attacker can leverage this vulnerability to execute code in the context of the service account. Was ZDI-CAN-17434.

Read the notes from the security team

Status

Package Ubuntu Release Status
exim4 23.10 mantic
Fixed 4.96-17ubuntu2
23.04 lunar
Fixed 4.96-14ubuntu1.2
22.04 LTS jammy
Fixed 4.95-4ubuntu2.3
20.04 LTS focal
Fixed 4.93-13ubuntu1.8
18.04 LTS bionic
Not affected
16.04 LTS xenial
Not affected
14.04 LTS trusty
Not affected

Notes

eslerm

no security patches available, see ZDI’s timeline

allenpthuang

patches now available, see the thread on Openwall

Severity score breakdown

Parameter Value
Base score 9.8 · Critical
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Scope Unchanged
Confidentiality High
Integrity impact High
Availability impact High
Vector CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H