CVE-2021-34432

Publication date 27 July 2021

Last updated 25 August 2025

Ubuntu priority

Cvss 3 Severity Score

Description

In Eclipse Mosquitto versions 2.07 and earlier, the server will crash if the client tries to send a PUBLISH packet with topic length = 0.

Read the notes from the security team

Status

Show unmaintained releases

Package	Ubuntu Release	Status
mosquitto	23.10 mantic	Not affected
	23.04 lunar	Not affected
	22.10 kinetic	Not affected
	22.04 LTS jammy	Not affected
	21.10 impish	Not affected
	21.04 hirsute	Not affected
	20.04 LTS focal	Not affected
	18.04 LTS bionic	Not affected
	16.04 LTS xenial	Not affected
	14.04 LTS trusty	Not affected

Notes

gianz

PoC: https://bugs.eclipse.org/bugs/show_bug.cgi?id=574141 (first message) The CVE indicates versions <= 2.0.7 as affected. However only versions >= 2.0.0 and <= 2.0.7 are vulnerable. No crash detected running the PoC against any previous version we support.

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:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H