Resource Exhaustion Affecting zeromq3 package, versions <4.3.2-2ubuntu1.20.04.1~esm2


Severity

Recommended
low

Based on Ubuntu security rating.

Threat Intelligence

EPSS
1.69% (75th percentile)

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  • Snyk IDSNYK-UBUNTU2004-ZEROMQ3-1126476
  • published21 Mar 2026
  • disclosed28 May 2021

Introduced: 28 May 2021

CVE-2021-20237  (opens in a new tab)
CWE-400  (opens in a new tab)

How to fix?

Upgrade Ubuntu:20.04 zeromq3 to version 4.3.2-2ubuntu1.20.04.1~esm2 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream zeromq3 package and not the zeromq3 package as distributed by Ubuntu. See How to fix? for Ubuntu:20.04 relevant fixed versions and status.

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.

CVSS Base Scores

version 3.1