CVE Tools
Sign in

CVE-2021-34583

CODESYS V2 web server: crafted requests could trigger a heap-based buffer overflow (DoS)

Published: Oct 26, 2021Updated: Aug 15, 2025 Sources: CVE List NVDCWE-122
NVD MITRE
7.5CVSSHIGH
EPSS Score
8.4%
Top 5.7%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
Patch Available

Description

Crafted web server requests may cause a heap-based buffer overflow and could therefore trigger a denial-of- service condition due to a crash in the CODESYS V2 web server prior to V1.1.9.22.

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-122CWE-787

Affected Products

CODESYS V2CODESYSICS / OT / IoT
750-8214 firmwarewagoICS / OT / IoT
750-8216 firmwarewagoICS / OT / IoT
750-8217 firmwarewagoICS / OT / IoT
750-8213 firmwarewagoICS / OT / IoT
codesysoss-projectDEICS / OT / IoTaka codesys gmbh
wagocommercialDEICS / OT / IoT
and 24 more affected products View all →

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

2 techniques
Initial Access
Privilege Escalation
View detailed technique mapping

References

https://customers.codesys.com/index.php?eID=dumpFile&t=f&f=16876&token=a3f1d937f95e7034879f4f2ea8e5a99b168256a7&download=
customers.codesys.com
https://www.tenable.com/security/research/tra-2021-47
tenable.com

Timeline

Published
Oct 26, 2021
Last Updated
Aug 15, 2025

Unlock Complete Vulnerability Intelligence

Get the full picture for CVE-2021-34583 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