CVE-2017-16944

Publication date 27 November 2017

Last updated 25 August 2025

Ubuntu priority

Cvss 3 Severity Score

Description

The receive_msg function in receive.c in the SMTP daemon in Exim 4.88 and 4.89 allows remote attackers to cause a denial of service (infinite loop and stack exhaustion) via vectors involving BDAT commands and an improper check for a '.' character signifying the end of the content, related to the bdat_getc function.

Read the notes from the security team

Status

Show unmaintained releases

Package	Ubuntu Release	Status
exim4	17.10 artful	Fixed 4.89-5ubuntu1.2
	17.04 zesty	Fixed 4.88-5ubuntu1.3
	16.04 LTS xenial	Not affected
	14.04 LTS trusty	Not affected

Notes

mdeslaur

only affects Exim 4.88 or newer

Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package	Patch details
exim4	Upstream: 178ecb7 Upstream: 4804c62

Severity score breakdown

Parameter	Value
Base score	7.5 · High
Attack vector	Network
Attack complexity	Low
Privileges required	None
User interaction	None
Scope	Unchanged
Confidentiality	None
Integrity impact	None
Availability impact	High
Vector	CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H