Is CVE-2021-30188 actively exploited?

No active exploitation of CVE-2021-30188 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2021-30188 be exploited remotely?

Yes. CVE-2021-30188 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2021-30188?

CVE-2021-30188 has a CVSS score of 9.8 (CRITICAL).

HOME VULNERABILITIESCVE-2021-30188

CRITICAL

CVE-2021-30188

CWE-787Published: May 25, 2021· Updated: Jun 17, 2026

9.8

CVSS v3.1

Official Description

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

NVD Source

Technical Analysis

CVE-2021-30188 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 9.8.

From a weakness classification perspective (CWE-787): Out-of-bounds write vulnerabilities can lead to data corruption, crashes, or arbitrary code execution.

CVSS v3.1 Vector Breakdown

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges Req.None

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected Vendors & Products

codesys1 product(s)

v2 runtime system sp

wago54 product(s)

750-893 firmware750-893750-891 firmware750-891750-890 firmware750-890750-889 firmware750-889750-885 firmware750-885750-882 firmware750-882+42

Source: NVD CPE · 55 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time

Exploit-DB

Offensive Security exploit database

GitHub PoC Search

Community PoC repositories

Rapid7 / Metasploit

Metasploit module search

PacketStorm

Security advisories & exploits

External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

ADVISORYhttps://customers.codesys.com/index.php

ADVISORYhttps://customers.codesys.com/index.php?eID=dumpFile&t=f&f=14725&token=08691519ef764b252630759eff925890176ecd78&download=

ADVISORYhttps://customers.codesys.com/index.php

ADVISORYhttps://customers.codesys.com/index.php?eID=dumpFile&t=f&f=14725&token=08691519ef764b252630759eff925890176ecd78&download=

News & Research Mentioning CVE-2021-30188

CODESYS in Festo Automation Suite

CISA Alerts· Mar 17, 2026

View CSAF Summary 3. TECHNICAL DETAILS The following versions of CODESYS in Festo Automation Suite are affected: FESTO Software Festo Automation Suite (versions prior to 2.8.0.138) installed with CODESYS Software CODESYS Development System (3.0) vers:all/* FESTO Software Festo Automation Suite (versions prior to 2.8.0.138) installed with CODESYS Software CODESYS Development System (3.5.16.10) vers:all/* FESTO Software Festo Automation Suite (2.8.0.137) installed with CODESYS Software CODESYS Development System (3.0) vers:all/* FESTO Software Festo Automation Suite (2.8.0.137) installed with CODESYS Software CODESYS Development System (3.5.16.10) vers:all/* CVSS Vendor Equipment Vulnerabilities v3 9.8 FESTO, CODESYS CODESYS in Festo Automation Suite D [xlite_meta score:79 src:CISA Alerts xlite_fp:17fca52d9c8a749f3ecbaf32eff92f14e856489804a56a18cc6c0d7f4acd2a9d]