CVE-2020-12526 - CVE House
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Status published Medium CVE-2020-12526

BECKHOFF: DoS-Vulnerability for TwinCAT OPC UA Server and IPC Diagnostics UA Server

Vulnerability Description

TwinCAT OPC UA Server in versions up to 2.3.0.12 and IPC Diagnostics UA Server in versions up to 3.1.0.1 from Beckhoff Automation GmbH & Co. KG are vulnerable to denial of service attacks. The attacker needs to send several specifically crafted requests to the running OPC UA server. After some of these requests the OPC UA server is no longer responsive to any client. This is without effect to the real-time functionality of IPCs.

Impact Analysis

Refer to official advisory for detailed impact metrics.

Remediation

Ensure systems are updated to the latest vendor-supplied patch levels.

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Credits & Attribution

The following person or organization is credited with identifying this vulnerability, as recorded in the NVD database:

  • Beckhoff Automation thanks Industrial Control Security Laboratory of QI-ANXIN Technology Group Inc. from China for reporting the issue and for support and efforts with the coordinated disclosure. Also Beckhoff Automation thanks CERT@VDE for coordination.

References

More from Beckhoff

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CVE-2025-41701
Beckhoff: Deserialization of untrusted data by TwinCAT 3 Engineering
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CVE-2024-8934
Beckhoff: Local command injection via TwinCAT Package Manager
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CVE-2024-41176
Beckhoff: Local Denial of Service issue in package MDP included in TwinCAT/BSD
High 7.3
CVE-2024-41175
Beckhoff: Local Denial-of-Service vulnerability in TwinCAT/BSD and the IPC-Diagnostics package
Medium 5.5
CVE-2024-41174
Beckhoff: Improper input neutralization vulnerability in the IPC-Diagnostics package in TwinCAT/BSD
High 7.3

Affected Vendor

Affected Software

TwinCAT OPC UA Server, IPC Diagnostics UA Server, TF6100
Vulnerable Versions:
unspecified

Timeline

Official Publish: May 13th, 2021
Last Modified: September 16th, 2024
Added to House: July 21st, 2026

CVSS Vectors

V3: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Weaknesses (CWE)

CWE-20

MITRE ATT&CK TTPs

T1190 Exploit Public-Facing Application
Initial Access
T1059 Command and Scripting Interpreter
Execution
T1068 Exploitation for Privilege Escalation
Privilege Escalation
T1213 Data from Information Repositories
Collection
T1565.002 Stored Data Manipulation
Impact