CVE-2023-51766
- State
- Published
- Severity
- Not scored
- Published
- Dec 24, 2023
- Updated
- Nov 4, 2025
- Reserved
- Dec 24, 2023
Description
Exim before 4.97.1 allows SMTP smuggling in certain PIPELINING/CHUNKING configurations. Remote attackers can use a published exploitation technique to inject e-mail messages with a spoofed MAIL FROM address, allowing bypass of an SPF protection mechanism. This occurs because Exim supports <LF>.<CR><LF> but some other popular e-mail servers do not.
Scores
The record has no CVSS score.
Weaknesses
The record names no weakness.
Affected Products
| Product | Versions |
|---|---|
n/an/a |
|
References
- https://sec-consult.com/blog/detail/smtp-smuggling-spoofing-e-mails-worldwide/
- https://exim.org/static/doc/security/CVE-2023-51766.txt
- https://bugs.exim.org/show_bug.cgi?id=3063
- https://www.openwall.com/lists/oss-security/2023/12/23/2
- [oss-security] 20231224 Re: Re: New SMTP smuggling attackmailing-list
- [oss-security] 20231225 Re: Re: New SMTP smuggling attackmailing-list
- https://git.exim.org/exim.git/commit/5bb786d5ad568a88d50d15452aacc8404047e5ca
- https://git.exim.org/exim.git/commit/cf1376206284f2a4f11e32d931d4aade34c206c5
- https://bugzilla.redhat.com/show_bug.cgi?id=2255852
- https://fahrplan.events.ccc.de/congress/2023/fahrplan/events/11782.html
- [oss-security] 20231229 CVE-2023-51766: Exim: SMTP smugglingmailing-list
- https://github.com/Exim/exim/blob/master/doc/doc-txt/cve-2023-51766
- [oss-security] 20240101 Re: CVE-2023-51766: Exim: SMTP smugglingmailing-list
- [oss-security] 20240101 Re: CVE-2023-51766: Exim: SMTP smugglingmailing-list
- [oss-security] 20240101 Re: CVE-2023-51766: Exim: SMTP smugglingmailing-list
- https://www.youtube.com/watch?v=V8KPV96g1To
- [debian-lts-announce] 20240105 [SECURITY] [DLA 3708-1] exim4 security updatemailing-list
- FEDORA-2024-1ef6197a49vendor-advisory
- FEDORA-2024-e0841c83bbvendor-advisory
- https://lwn.net/Articles/956533/
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/ORN7OKEQPPBKUHYRQ6LR5PSNBQVDHAWB/
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/QPDWHJPABVJCXDSNELSSVTIVAJU2MDUQ/
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