HOMEVULNERABILITIESCVE-2021-21000
HIGH

CVE-2021-21000

CWE-770Published: May 24, 2021· Updated: Jun 17, 2026

7.5
CVSS v3.1

Official Description

On WAGO PFC200 devices in different firmware versions with special crafted packets an attacker with network access to the device could cause a denial of service for the login service of the runtime.

NVD Source

Technical Analysis

CVE-2021-21000 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

wago54 product(s)
750-823 firmware750-823750-829 firmware750-829750-831 firmware750-831750-832 firmware750-832750-852 firmware750-852750-862 firmware750-862+42
Source: NVD CPE · 54 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
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Official Patches & Advisories

All References (2)

Quick Facts

CVE IDCVE-2021-21000
CVSS Score7.5 / 10
SeverityHIGH
WeaknessCWE-770
CISA KEVNo
Affected1 vendor(s)
PublishedMay 24, 2021

Related CVEs (CWE-770)

Recommended Actions

  • Apply vendor patches immediately
  • Monitor CVE-2021-21000 in threat intel feeds
  • Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.