CVE-2021-34434

Publication date 30 August 2021

Last updated 25 August 2025

Ubuntu priority

Cvss 3 Severity Score

Description

In Eclipse Mosquitto versions 2.0 to 2.0.11, when using the dynamic security plugin, if the ability for a client to make subscriptions on a topic is revoked when a durable client is offline, then existing subscriptions for that client are not revoked.

Status

Show unmaintained releases

Package	Ubuntu Release	Status
mosquitto	23.10 mantic	Not affected
	23.04 lunar	Fixed 2.0.11-1.2ubuntu0.1
	22.10 kinetic	Ignored end of life, was needs-triage
	22.04 LTS jammy	Fixed 2.0.11-1ubuntu1.1
	21.10 impish	Ignored end of life
	21.04 hirsute	Ignored end of life
	20.04 LTS focal	Not affected
	18.04 LTS bionic	Not affected
	16.04 LTS xenial	Not affected
	14.04 LTS trusty	Not affected

Severity score breakdown

Parameter	Value
Base score	5.3 · Medium
Attack vector	Network
Attack complexity	Low
Privileges required	None
User interaction	None
Scope	Unchanged
Confidentiality	Low
Integrity impact	None
Availability impact	None
Vector	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

References

Related Ubuntu Security Notices (USN)

USN-6492-1
Mosquitto vulnerabilities
21 November 2023