CVE-2023-51766
What it is
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.
At a glance
- Exploitability
- Can be exploited over the network without logging in. Limited direct impact.
- Exploit odds
- 1.1% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 1.1% in the next 30 days (EPSS).
- Severity: 5.3 MEDIUM (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 1.1% · EPSS, next 30 days
- Weakness
- CWE-345
- Record status
- Modified
Affected
- Exim < 4.97.1
- Fedoraproject Extra Packages For Enterprise Linux 7.0
- Fedoraproject Extra Packages For Enterprise Linux 8.0
- Fedoraproject Extra Packages For Enterprise Linux 9.0
- Fedoraproject Fedora 38
- Fedoraproject Fedora 39
- Debian Linux 10.0
Attack profile CVSS 3.1 · 5.3
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- Low
- Availability
- None
Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2023-51766.md and follow it. Check whether this project is affected by CVE-2023-51766. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- http://www.openwall.com/lists/oss-security/2023/12/29/2
- https://bugs.exim.org/show_bug.cgi?id=3063
- https://git.exim.org/exim.git/commit/5bb786d5ad568a88d50d15452aacc8404047e5ca
- https://git.exim.org/exim.git/commit/cf1376206284f2a4f11e32d931d4aade34c206c5
- https://github.com/Exim/exim/blob/master/doc/doc-txt/cve-2023-51766
- http://www.openwall.com/lists/oss-security/2023/12/29/2
- https://bugs.exim.org/show_bug.cgi?id=3063
- https://git.exim.org/exim.git/commit/5bb786d5ad568a88d50d15452aacc8404047e5ca
- https://git.exim.org/exim.git/commit/cf1376206284f2a4f11e32d931d4aade34c206c5
- https://github.com/Exim/exim/blob/master/doc/doc-txt/cve-2023-51766
References
- http://www.openwall.com/lists/oss-security/2023/12/24/1
- http://www.openwall.com/lists/oss-security/2023/12/25/1
- http://www.openwall.com/lists/oss-security/2023/12/29/2
- http://www.openwall.com/lists/oss-security/2024/01/01/1
- http://www.openwall.com/lists/oss-security/2024/01/01/2
- http://www.openwall.com/lists/oss-security/2024/01/01/3
- https://bugs.exim.org/show_bug.cgi?id=3063
- https://bugzilla.redhat.com/show_bug.cgi?id=2255852
- https://exim.org/static/doc/security/CVE-2023-51766.txt
- https://fahrplan.events.ccc.de/congress/2023/fahrplan/events/11782.html
- https://git.exim.org/exim.git/commit/5bb786d5ad568a88d50d15452aacc8404047e5ca
- https://git.exim.org/exim.git/commit/cf1376206284f2a4f11e32d931d4aade34c206c5
- https://github.com/Exim/exim/blob/master/doc/doc-txt/cve-2023-51766
- https://lists.debian.org/debian-lts-announce/2024/01/msg00002.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ORN7OKEQPPBKUHYRQ6LR5PSNBQVDHAWB/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QPDWHJPABVJCXDSNELSSVTIVAJU2MDUQ/
- https://lwn.net/Articles/956533/
- https://sec-consult.com/blog/detail/smtp-smuggling-spoofing-e-mails-worldwide/
- https://www.openwall.com/lists/oss-security/2023/12/23/2
- https://www.youtube.com/watch?v=V8KPV96g1To
- http://www.openwall.com/lists/oss-security/2023/12/24/1
- http://www.openwall.com/lists/oss-security/2023/12/25/1
- http://www.openwall.com/lists/oss-security/2023/12/29/2
- http://www.openwall.com/lists/oss-security/2024/01/01/1
- http://www.openwall.com/lists/oss-security/2024/01/01/2