VulnerabilityModified
CVE-2023-51766
Exim before 4.97.1 allows SMTP smuggling in certain PIPELINING/CHUNKING configurations.
MEDIUM 5.3EPSS 1.10%
Does this matter?
Lower severity and a low EPSS score (1.10%). Track it; it rarely justifies an emergency change on its own.
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.
- CVSS 3.1
- 5.3 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
- EPSS
- 1.10% probability · 64th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-345
- Affected
- exim/exim · fedoraproject/extra packages for enterprise linux · fedoraproject/fedora · debian/debian linux
- Source
- cve@mitre.org
References
- http://www.openwall.com/lists/oss-security/2023/12/24/1Mailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2023/12/25/1Mailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2023/12/29/2Mailing List, Mitigation, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2024/01/01/1Mailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2024/01/01/2Mailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2024/01/01/3Mailing List, Third Party Advisory
- https://bugs.exim.org/show_bug.cgi?id=3063Issue Tracking, Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2255852Issue Tracking, Third Party Advisory
- https://exim.org/static/doc/security/CVE-2023-51766.txtBroken Link
- https://fahrplan.events.ccc.de/congress/2023/fahrplan/events/11782.htmlTechnical Description
- https://git.exim.org/exim.git/commit/5bb786d5ad568a88d50d15452aacc8404047e5caPatch
- https://git.exim.org/exim.git/commit/cf1376206284f2a4f11e32d931d4aade34c206c5Patch
- https://github.com/Exim/exim/blob/master/doc/doc-txt/cve-2023-51766Mitigation, Vendor Advisory
- https://lists.debian.org/debian-lts-announce/2024/01/msg00002.htmlMailing List, Third Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ORN7OKEQPPBKUHYRQ6LR5PSNBQVDHAWB/Mailing List, Third Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QPDWHJPABVJCXDSNELSSVTIVAJU2MDUQ/Mailing List, Third Party Advisory
- https://lwn.net/Articles/956533/Third Party Advisory
- https://sec-consult.com/blog/detail/smtp-smuggling-spoofing-e-mails-worldwide/Technical Description, Third Party Advisory
- https://www.openwall.com/lists/oss-security/2023/12/23/2Issue Tracking, Mailing List, Third Party Advisory
- https://www.youtube.com/watch?v=V8KPV96g1ToExploit
- http://www.openwall.com/lists/oss-security/2023/12/24/1Mailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2023/12/25/1Mailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2023/12/29/2Mailing List, Mitigation, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2024/01/01/1Mailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2024/01/01/2Mailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2024/01/01/3Mailing List, Third Party Advisory
- https://bugs.exim.org/show_bug.cgi?id=3063Issue Tracking, Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2255852Issue Tracking, Third Party Advisory
- https://exim.org/static/doc/security/CVE-2023-51766.txtBroken Link
- https://fahrplan.events.ccc.de/congress/2023/fahrplan/events/11782.htmlTechnical Description
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.