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

Show unmaintained releases

Package	Ubuntu Release	Status
exim4	24.04 LTS noble	Fixed 4.97-3
	23.10 mantic	Fixed 4.96-17ubuntu2.2
	23.04 lunar	Ignored
	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 Ubuntu Pro
	16.04 LTS xenial	Fixed 4.86.2-2ubuntu2.6+esm6 Ubuntu Pro
	14.04 LTS trusty	Needs evaluation

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Severity 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