CVE-2021-20234 Denial of service in zeromq
A memory leak in the ZeroMQ client allows malicious servers to crash connecting clients, impacting system availability.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2021-20234?
CVE-2021-20234 is a medium-severity denial of service vulnerability in zeromq, published on 1 Apr 2021. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
An uncontrolled resource consumption (memory leak) flaw was found in the ZeroMQ client in versions before 4.3.3 in src/pipe.cpp. This issue causes a client that connects to multiple malicious or compromised servers to crash. The highest threat from this vulnerability is to system availability.
Which versions are affected by CVE-2021-20234?
It affects 1 product.
Products include Zeromq Libzmq.
How do I fix CVE-2021-20234?
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-2021-20234 being exploited?
There is no known exploitation of CVE-2021-20234 in the wild and no public exploit code.
Other vulnerabilities in zeromq
Sources
Also known as DEBIAN-CVE-2021-20234, GHSA-47vr-832f-crm9, GHSA-wfr2-29gj-5w87, JLSEC-2026-514, UBUNTU-CVE-2021-20234.