CVE-2017-16944
Description
The receive_msg function in receive.c in the SMTP daemon in Exim 4.88 and 4.89 allows remote attackers to cause a denial of service (infinite loop and stack exhaustion) via vectors involving BDAT commands and an improper check for a '.' character signifying the end of the content, related to the bdat_getc function.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
Exploits
Public proof-of-concept code below. AS-IS, for defenders and authorised testing only.
Exploit-DB
OS impact
| OS | Version | Status | Fixed in |
|---|---|---|---|
| arch | fixed | 4.89.1-1 | |
| debian | bookworm | fixed | 4.89-13 |
| debian | bullseye | fixed | 4.89-13 |
| debian | forky | fixed | 4.89-13 |
| debian | sid | fixed | 4.89-13 |
| debian | trixie | fixed | 4.89-13 |
| debian | 9.0 | affected | |
References
- https://security.archlinux.org/ASA-201711-32
- http://openwall.com/lists/oss-security/2017/11/25/1
- http://openwall.com/lists/oss-security/2017/11/25/2
- http://openwall.com/lists/oss-security/2017/11/25/3
- http://www.openwall.com/lists/oss-security/2021/05/04/7
- http://www.securitytracker.com/id/1039873
- https://bugs.exim.org/show_bug.cgi?id=2201
- https://lists.exim.org/lurker/message/20171125.034842.d1d75cac.en.html
- https://www.debian.org/security/2017/dsa-4053
- https://www.exploit-db.com/exploits/43184/
- https://security-tracker.debian.org/tracker/CVE-2017-16944
CWEs
CWE-835
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.