CVE-2018-12551

Name	CVE-2018-12551
Description	When Eclipse Mosquitto version 1.0 to 1.5.5 (inclusive) is configured to use a password file for authentication, any malformed data in the password file will be treated as valid. This typically means that the malformed data becomes a username and no password. If this occurs, clients can circumvent authentication and get access to the broker by using the malformed username. In particular, a blank line will be treated as a valid empty username. Other security measures are unaffected. Users who have only used the mosquitto_passwd utility to create and modify their password files are unaffected by this vulnerability.
Source	CVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
References	DLA-1972-1, DSA-4388-1
Debian Bugs	921976

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
mosquitto (PTS)	jessie, jessie (lts)	1.3.4-2+deb8u4	fixed
	stretch (security), stretch (lts), stretch	1.4.10-3+deb9u5	fixed
	buster (security), buster, buster (lts)	1.5.7-1+deb10u1	fixed
	bullseye (security), bullseye	2.0.11-1+deb11u1	fixed
	bookworm (security), bookworm	2.0.11-1.2+deb12u1	fixed
	sid, trixie	2.0.20-1	fixed

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
mosquitto	source	wheezy	(unfixed)	end-of-life
mosquitto	source	jessie	1.3.4-2+deb8u4		DLA-1972-1
mosquitto	source	stretch	1.4.10-3+deb9u3		DSA-4388-1
mosquitto	source	(unstable)	1.5.6-1			921976

https://mosquitto.org/blog/2019/02/version-1-5-6-released/
https://mosquitto.org/files/cve/2018-12551