Debian DSA-4053-1 : exim4 - security update

critical Nessus Plugin ID 104940


The remote Debian host is missing a security-related update.


Several vulnerabilities have been discovered in Exim, a mail transport agent. The Common Vulnerabilities and Exposures project identifies the following issues :

- CVE-2017-16943 A use-after-free vulnerability was discovered in Exim's routines responsible for parsing mail headers. A remote attacker can take advantage of this flaw to cause Exim to crash, resulting in a denial of service, or potentially for remote code execution.

- CVE-2017-16944 It was discovered that Exim does not properly handle BDAT data headers allowing a remote attacker to cause Exim to crash, resulting in a denial of service.


Upgrade the exim4 packages.

For the stable distribution (stretch), these problems have been fixed in version 4.89-2+deb9u2. Default installations disable advertising the ESMTP CHUNKING extension and are not affected by these issues.

See Also

Plugin Details

Severity: Critical

ID: 104940

File Name: debian_DSA-4053.nasl

Version: 3.7

Type: local

Agent: unix

Published: 12/1/2017

Updated: 1/4/2021

Supported Sensors: Frictionless Assessment Agent, Nessus Agent, Agentless Assessment, Nessus

Risk Information


Risk Factor: Medium

Score: 6.7


Risk Factor: High

Base Score: 7.5

Temporal Score: 5.9

Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P


Risk Factor: Critical

Base Score: 9.8

Temporal Score: 8.8

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Temporal Vector: CVSS:3.0/E:P/RL:O/RC:C

Vulnerability Information

CPE: p-cpe:/a:debian:debian_linux:exim4, cpe:/o:debian:debian_linux:9.0

Required KB Items: Host/local_checks_enabled, Host/Debian/release, Host/Debian/dpkg-l

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 11/30/2017

Reference Information

CVE: CVE-2017-16943, CVE-2017-16944

DSA: 4053