Vulnerability Details CVE-2020-12510
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.
Exploit prediction scoring system (EPSS) score
EPSS Score 0.002
EPSS Ranking 43.4%
CVSS Severity
CVSS v3 Score 7.3
CVSS v2 Score 6.0
References
Products affected by CVE-2020-12510
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cpe:2.3:a:beckhoff:twincat_extended_automation_runtime:3.1