Arch Linux: ASA-201810-1 Medium Severity: Mosquitto Denial Of Service

Arch Linux Security Advisory ASA-201810-1
========================================
Severity: Medium
Date    : 2018-10-01
CVE-ID  : CVE-2018-12543
Package : mosquitto
Type    : denial of service
Remote  : Yes
Link    : https://security.archlinux.org/AVG-772

Summary
======
The package mosquitto before version 1.5.3-1 is vulnerable to denial of
service.

Resolution
=========
Upgrade to 1.5.3-1.

# pacman -Syu "mosquitto>=1.5.3-1"

The problem has been fixed upstream in version 1.5.3.

Workaround
=========
None.

Description
==========
If a message is sent to Mosquitto before 1.5.3 with a topic that begins
with $, but is not $SYS, then an assert that should be unreachable is
triggered and Mosquitto will exit.

Impact
=====
A remote attacker is able to cause a denial of service by sending a
specially crafted mqtt message.

References
=========
https://mosquitto.org/blog/2018/09/security-advisory-cve-2018-12543/
https://github.com/eclipse-mosquitto/mosquitto/commit/f7474d348225bf086f6b9c69b18d6413aa6ffca6
https://security.archlinux.org/CVE-2018-12543