CVE Tools
Sign in

CVE-2021-30186

CODESYS V2 runtime system SP before 2.4.7.55 has a Heap-based Buffer Overflow.

Published: May 25, 2021Updated: Aug 15, 2025 Sources: CVE List NVD BDU csafCWE-787
NVD MITRE
7.5CVSSHIGH
EPSS Score
7.4%
Top 6.4%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
Patch Available

Description

Starting with Festo Automation Suite (FAS) version 2.8.0.138, the suite is delivered only with a connector to Codesys, rather than including Codesys directly. Prior to this version, Codesys was bundled within the FAS installation. From version 2.8.0.138 onwards, customers are required to download and install Codesys independently. This change impacts the handling of security vulnerabilities (CVEs) related to Codesys. Any Codesys-related security issues must now be addressed by the customer through their separate Codesys installation. The FAS itself includes only the connector component, which is maintained and updated within the suite. Please ensure that Codesys is kept up to date independently to mitigate any potential security risks associated with the Codesys software.

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-787

Affected Products

750-893 firmwarewagoICS / OT / IoT
750-891 firmwarewagoICS / OT / IoT
750-890 firmwarewagoICS / OT / IoT
750-889 firmwarewagoICS / OT / IoT
750-885 firmwarewagoICS / OT / IoT
wagocommercialDEICS / OT / IoT
and 26 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://festo.csaf-tp.certvde.com/.well-known/csaf/white/2026/fsa-202601.json
festo.csaf-tp.certvde.com
https://certvde.com/en/advisories/vendor/festo/
certvde.com
https://www.festo.com/psirt
festo.com
and 229 more references View all →

Timeline

Published
May 25, 2021
Last Updated
Aug 15, 2025

Unlock Complete Vulnerability Intelligence

Get the full picture for CVE-2021-30186 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