CVE-2020-12510

Beckhoff: Privilege Escalation through TwinCat System

HIGH
7.3
CVSS Score
Published: November 19, 2020 at 05:07 PM UTC
Updated: June 17, 2026 at 02:51 AM UTC
1 product affected across 1 vendorTwincat Extended Automation Runtime

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Severity
HIGH7.3
Exploit prediction
EPSS 0.9%

Description

The default installation path of the TwinCAT XAR 3.1 software in all versions is underneath C:\TwinCAT. If the directory does not exist it and further subdirectories are created with permissions which allow every local user to modify the content. The default installation registers TcSysUI.exe for automatic execution upon log in of a user. If a less privileged user has a local account he or she can replace TcSysUI.exe. It will be executed automatically by another user during login. This is also true for users with administrative access. Consequently, a less privileged user can trick a higher privileged user into executing code he or she modified this way. By default Beckhoff’s IPCs are shipped with TwinCAT software installed this way and with just a single local user configured. Thus the vulnerability exists if further less privileged users have been added.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

References (1)

x_refsource_CONFIRMThird Party Advisory
https://cert.vde.com/en-us/advisories/vde-2020-037

CVSS

7.3HIGHCERTVDE
Attack Vector
LOCAL
Complexity
LOW
Privileges
LOW
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-276

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