Is CVE-2021-34583 actively exploited?

No active exploitation of CVE-2021-34583 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2021-34583 be exploited remotely?

Yes. CVE-2021-34583 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2021-34583?

CVE-2021-34583 has a CVSS score of 7.5 (HIGH).

HOME VULNERABILITIESCVE-2021-34583

HIGH

CVE-2021-34583

CWE-122Published: October 26, 2021· Updated: Jun 17, 2026

7.5

CVSS v3.1

Official 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.

NVD Source

Technical Analysis

CVE-2021-34583 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 availability disruption (denial of service), with a CVSS base score of 7.5.

CVSS v3.1 Vector Breakdown

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges Req.None

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityNone

IntegrityNone

AvailabilityHigh

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

Affected Vendors & Products

codesys1 product(s)

codesys

wago54 product(s)

750-8214 firmware750-8214750-8216 firmware750-8216750-8217 firmware750-8217750-8213 firmware750-8213750-8212 firmware750-8212750-8211 firmware750-8211+42

Source: NVD CPE · 55 total CPE entries