CVE-2020-12510 Beckhoff: Privilege Escalation through TwinCat System
A local attacker can replace a system executable to execute arbitrary code with higher privileges when another user logs in.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2020-12510?
CVE-2020-12510 is a high-severity vulnerability in Beckhoff TwinCat XAR 3.1, published on 19 Nov 2020. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official 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.
Weakness: CWE-276
Which versions are affected by CVE-2020-12510?
It affects 1 product.
Products include Beckhoff Twincat Extended Automation Runtime.
How do I fix CVE-2020-12510?
No fix has been published for CVE-2020-12510 yet. Limit exposure of the affected software until one is available.
Is CVE-2020-12510 being exploited?
There is no known exploitation of CVE-2020-12510 in the wild and no public exploit code.
Sources
Also known as GHSA-63jm-rmjc-h9qh.