CVE-2021-20237

Name	CVE-2021-20237
Description	An uncontrolled resource consumption (memory leak) flaw was found in ZeroMQ's src/xpub.cpp in versions before 4.3.3. This flaw allows a remote unauthenticated attacker to send crafted PUB messages that consume excessive memory if the CURVE/ZAP authentication is disabled on the server, causing a denial of service. The highest threat from this vulnerability is to system availability.
Source	CVE (at NVD; CERT, LWN, oss-sec, fulldisc, bugtraq, EDB, Metasploit, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, Mageia, GitHub code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
zeromq3 (PTS)	buster, buster (security)	4.3.1-4+deb10u2	vulnerable
	bullseye	4.3.4-1	fixed
	bookworm, sid	4.3.4-2	fixed

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

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
zeromq3	source	(unstable)	4.3.3-1

Notes

[buster] - zeromq3 <no-dsa> (Minor issue)
[stretch] - zeromq3 <no-dsa> (Minor issue)
https://github.com/zeromq/libzmq/pull/3935
https://github.com/zeromq/libzmq/security/advisories/GHSA-4p5v-h92w-6wxw
https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=22344