HOMEVULNERABILITIESCVE-2019-5636
HIGH

CVE-2019-5636

CWE-404Published: November 21, 2019· Updated: Jun 17, 2026

7.5
CVSS v3.1

Official Description

When a Beckhoff TwinCAT Runtime receives a malformed UDP packet, the ADS Discovery Service shuts down. Note that the TwinCAT devices are still performing as normal. This issue affects TwinCAT 2 version 2304 (and prior) and TwinCAT 3.1 version 4204.0 (and prior).

NVD Source

Technical Analysis

CVE-2019-5636 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

beckhoff1 product(s)
twincat
Source: NVD CPE · 2 total CPE entries

Exploit & PoC Resources

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

All References (4)

Quick Facts

CVE IDCVE-2019-5636
CVSS Score7.5 / 10
SeverityHIGH
WeaknessCWE-404
CISA KEVNo
Affected1 vendor(s)
PublishedNov 21, 2019

Related CVEs (CWE-404)

Recommended Actions

  • Apply vendor patches immediately
  • Monitor CVE-2019-5636 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.