CVE Tools
Sign in

CVE-2021-20237

Published: May 28, 2021Updated: Nov 21, 2024 Sources: CVE List NVD BDUCWE-400
NVD MITRE
7.5CVSSHIGH
EPSS Score
1.7%
Top 25.9%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
Patch Available

Description

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 Vector Breakdown

AV:NAC:LPR:NUI:NS:UC:NI:NA:H
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:NPrivileges Required
None
UI:NUser Interaction
None
Scope
S:UScope
Unchanged
Impact
C:NConfidentiality
None
I:NIntegrity
None
A:HAvailability
High
Open in CVSS calculator →

Weaknesses

CWE-400CWE-401

Affected Products

zeromqn/a
libzmqzeromq
Library
OSS Libraries / generic-library
Debian GNU/LinuxСообщество свободного программного обеспечения
On-premOS
Operating Systems / linux-distro
Astra Linux Special EditionООО «РусБИТех-Астра»
On-premOS
Operating Systems / linux-distro
ZeroMQСообщество свободного программного обеспечения
On-prem
Operating Systems / linux-distro
zeromqoss-projectOSS Librariesaka libzmq, 0mq, zmq
сообщество свободного программного обеспеченияoss-projectOperating Systemsaka сообщество свободного программного обеспечения, fsf
ооо «русбитех-астра»commercialRUOperating Systemsaka rusbitech-astra

Attack Graph

Products CVE Techniques Tactics

Click technique nodes to view MITRE ATT&CK details. Scroll to zoom, drag to pan.

Exploitability

Official Patch Available

MITRE ATT&CK

1 technique
Impact
View detailed technique mapping

References

https://bugzilla.redhat.com/show_bug.cgi?id=1921989
bugzilla.redhat.com
https://github.com/zeromq/libzmq/security/advisories/GHSA-4p5v-h92w-6wxw
github.com
https://bugzilla.redhat.com/show_bug.cgi?id=1921989
bugzilla.redhat.com
and 5 more references View all →

Timeline

Published
May 28, 2021
Last Updated
Nov 21, 2024

Unlock Complete Vulnerability Intelligence

Get the full picture for CVE-2021-20237 and every CVE in our database. Create a free account — no credit card required.

Create Free Account
Plain-language analysis
Impact assessment and exploitation scenario in plain English
Attack graph visualization
Interactive attack path and kill chain mapping
Exploit details & PoC links
ExploitDB, Metasploit, GitHub PoCs with direct links
Nuclei scanner templates
Ready-to-use vulnerability scanner templates
Full remediation guide
Patch instructions, workarounds, and compliance impact
Interactive AI chat
Ask questions about this vulnerability in natural language
Related vulnerabilities
Semantically similar CVEs and attack patterns
REST API & MCP access
Integrate vulnerability data into your workflows