Description
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.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Exim | Exim | exim 4.95 | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | exim4 | 4.97~RC1-2 | — |
| Debian 13 | exim4 | 4.97~RC1-2 | — |
| Debian 12 | exim4 | 4.96-15+deb12u2 | DSA-5512-1 |
| Debian 11 | exim4 | 4.94.2-7+deb11u1 | DSA-5512-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 22.04 LTS | exim4 | 4.95-4ubuntu2.3 | USN-6411-1 |
| Ubuntu 20.04 LTS | exim4 | 4.93-13ubuntu1.8 | USN-6411-1 |
Show 3 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 18.04 LTS | exim4 | 4.90.1-1ubuntu1.10+esm1 | USN-6411-1 |
| Ubuntu Pro 16.04 LTS | exim4 | 4.86.2-2ubuntu2.6+esm4 | USN-6411-1 |
| Ubuntu Pro 14.04 LTS | exim4 | 4.82-3ubuntu2.4+esm6 | USN-6411-1 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SUSE Package Hub 15 SP5 | exim | 4.94.2-bp155.5.3.1 | openSUSE-SU-2024:0007-1, openSUSE-SU-2023:0293-1 |
| SUSE Package Hub 15 SP4 | exim | 4.94.2-bp155.5.3.1 | openSUSE-SU-2023:0293-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | exim | 4.96.1-1.1 | openSUSE-SU-2024:13282-1 |
| openSUSE Leap 15.5 | exim | 4.94.2-bp155.5.3.1 | openSUSE-SU-2024:0007-1, openSUSE-SU-2023:0293-1 |
| openSUSE Leap 15.4 | exim | 4.94.2-bp155.5.3.1 | openSUSE-SU-2023:0293-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | exim | 4.96.1-r0 | — |
| Alpine v3.23 | exim | 4.96.1-r0 | — |
| Alpine v3.22 | exim | 4.96.1-r0 | — |
| Alpine v3.21 | exim | 4.96.1-r0 | — |
| Alpine v3.20 | exim | 4.96.1-r0 | — |
Show 3 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.19 | exim | 4.96.1-r0 | — |
| Alpine v3.18 | exim | 4.96.1-r0 | — |
| Alpine v3.17 | exim | 4.96.1-r0 | — |
Wolfi
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Wolfi rolling | exim | 4.96.1-r0 | — |
Public exploits
Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.
GitHub 2 repositories
-
kirinse/cve-2023-42115 ★ 9 · Sep 2, 2024
This module exploits a vulnerability in the target service identified as CVE-2023-42115.
-
doaso/CVE-2023-42115 ★ 1 · Apr 8, 2026
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
Advisories 6
- USN-6411-1 exim4 vulnerabilities Ubuntu Security Notices (USN) · Jun 29, 2026
- WID-SEC-2023-2505 Exim: Mehrere Schwachstellen BSI CERT-Bund (WID) · Jun 10, 2026
- DSA-5512-1 exim4 - security update Debian Security (DSA / DLA) · Mar 9, 2026
- openSUSE-SU-2023:0293-1 Security update for exim SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:13282-1 exim-4.96.1-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:0007-1 Security update for exim SUSE / openSUSE Security Updates · Feb 4, 2026