Description
Exim through 4.97.1 misparses a multiline RFC 2231 header filename, and thus remote attackers can bypass a $mime_filename extension-blocking protection mechanism, and potentially deliver executable attachments to the mailboxes of end users.
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 | 4.98~RC3-2 | — |
| Debian 13 | exim4 | 4.98~RC3-2 | — |
| Debian 12 | exim4 | 4.96-15+deb12u5 | DSA-5728-1 |
| Debian 11 | exim4 | 4.94.2-7+deb11u3 | DSA-5728-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 24.04 LTS | exim4 | 4.97-4ubuntu4.1 | USN-6939-1 |
| Ubuntu 22.04 LTS | exim4 | 4.95-4ubuntu2.6 | USN-6939-1 |
| Ubuntu 20.04 LTS | exim4 | 4.93-13ubuntu1.12 | USN-6939-1 |
Show 2 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+esm5 | USN-6939-1 |
| Ubuntu Pro 16.04 LTS | exim4 | 4.86.2-2ubuntu2.6+esm8 | USN-6939-1 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SUSE Package Hub 15 SP5 | exim | 4.97.1-bp155.5.12.1 | openSUSE-SU-2024:0218-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | exim | 4.98-1.1 | openSUSE-SU-2024:14196-1 |
| openSUSE Leap 15.5 | exim | 4.97.1-bp155.5.12.1 | openSUSE-SU-2024:0218-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | exim | 4.98-r0 | — |
| Alpine v3.23 | exim | 4.98-r0 | — |
| Alpine v3.22 | exim | 4.98-r0 | — |
| Alpine v3.21 | exim | 4.98-r0 | — |
| Alpine v3.20 | exim | 4.98-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
-
michael-david-fry/CVE-2024-39929 ★ 4 · Jul 29, 2024
POC to test CVE-2024-39929 against EXIM mail servers
-
rxerium/CVE-2024-39929 ★ 3 · Jul 12, 2024
Detection method for Exim vulnerability CVE-2024-39929
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
Advisories 5
- WID-SEC-2024-1527 Exim: Schwachstelle ermöglicht Umgehen von Sicherheitsvorkehrungen BSI CERT-Bund (WID) · Aug 13, 2026
- USN-6939-1 exim4 vulnerability Ubuntu Security Notices (USN) · Jun 25, 2026
- DSA-5728-1 exim4 - security update Debian Security (DSA / DLA) · Mar 9, 2026
- openSUSE-SU-2024:14196-1 exim-4.98-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:0218-1 Security update for exim SUSE / openSUSE Security Updates · Feb 4, 2026
References
- https://git.exim.org/exim.git/commit/6ce5c70cff8989418e05d01fd2a57703007a6357
- https://git.exim.org/exim.git/commit/1b3209b0577a9327ebb076f3b32b8a159c253f7b
- https://github.com/Exim/exim/compare/exim-4.98-RC2...exim-4.98-RC3
- https://www.rfc-editor.org/rfc/rfc2231.txt
- https://bugs.exim.org/show_bug.cgi?id=3099#c4