CVE-2021-41039 Denial of service in Eclipse Mosquitto

High 7.5 Published 1 Dec 2021 Updated 4 Aug 2024

An attacker can cause excessive CPU usage and potential denial of service in Eclipse Mosquitto by sending an MQTT v5 client connection with many user-property properties.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: Available

What is CVE-2021-41039?

CVE-2021-41039 is a high-severity denial of service vulnerability in The Eclipse Foundation Eclipse Mosquitto, published on 1 Dec 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

In versions 1.6 to 2.0.11 of Eclipse Mosquitto, an MQTT v5 client connecting with a large number of user-property properties could cause excessive CPU usage, leading to a loss of performance and possible denial of service.

Weakness: CWE-1050

Which versions are affected by CVE-2021-41039?

It affects 1 product.

Products include Eclipse Mosquitto.

How do I fix CVE-2021-41039?

Upgrade to a fixed version.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2021-41039 being exploited?

There is no known exploitation of CVE-2021-41039 in the wild and no public exploit code.

Sources

Also known as DEBIAN-CVE-2021-41039, GHSA-5xp2-36v8-r67m, OESA-2022-1498, UBUNTU-CVE-2021-41039.