CVE-2023-51766
Publication date 24 December 2023
Last updated 24 July 2024
Ubuntu priority
Cvss 3 Severity Score
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.
Status
Package | Ubuntu Release | Status |
---|---|---|
exim4 | 24.10 oracular |
Fixed 4.97-3
|
24.04 LTS noble |
Fixed 4.97-3
|
|
22.04 LTS jammy |
Fixed 4.95-4ubuntu2.5
|
|
20.04 LTS focal |
Fixed 4.93-13ubuntu1.10
|
|
18.04 LTS bionic |
Fixed 4.90.1-1ubuntu1.10+esm3
|
|
16.04 LTS xenial |
Fixed 4.86.2-2ubuntu2.6+esm6
|
|
14.04 LTS trusty |
Needs evaluation
|
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Get Ubuntu ProSeverity score breakdown
Parameter | Value |
---|---|
Base score | 5.3 · Medium |
Attack vector | Network |
Attack complexity | Low |
Privileges required | None |
User interaction | None |
Scope | Unchanged |
Confidentiality | None |
Integrity impact | Low |
Availability impact | None |
Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N |
References
Related Ubuntu Security Notices (USN)
- USN-6611-1
- Exim vulnerability
- 29 January 2024
Other references
- https://sec-consult.com/blog/detail/smtp-smuggling-spoofing-e-mails-worldwide/
- https://www.openwall.com/lists/oss-security/2023/12/21/6
- https://exim.org/static/doc/security/CVE-2023-51766.txt
- https://git.exim.org/exim.git/commit/cf1376206284f2a4f11e32d931d4aade34c206c5
- https://git.exim.org/exim.git/commit/4596719398f6f2365bed563aafd757a6433ce7b4
- https://git.exim.org/exim.git/commit/5bb786d5ad568a88d50d15452aacc8404047e5ca
- https://www.cve.org/CVERecord?id=CVE-2023-51766