CVE-2023-51766

Published: 24 December 2023

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.

Priority

Cvss 3 Severity Score

5.3

Score breakdown

Status

Package	Release	Status
exim4 Launchpad, Ubuntu, Debian	bionic	Released (4.90.1-1ubuntu1.10+esm3) Available with Ubuntu Pro or Ubuntu Pro (Infra-only)
	focal	Released (4.93-13ubuntu1.10)
	jammy	Released (4.95-4ubuntu2.5)
	lunar	Ignored (end of life, was needs-triage)
	mantic	Released (4.96-17ubuntu2.2)
	trusty	Needs triage
	upstream	Released (4.97-3)
	xenial	Released (4.86.2-2ubuntu2.6+esm6) Available with Ubuntu Pro or Ubuntu Pro (Infra-only)

Severity score breakdown

Parameter	Value
Base score	5.3
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

Bugs

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