Vulnerability in Beckhoff Twincat Extended Automation Runtime
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.3 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.009 (57.5th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 58th percentile — 57.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.009 · newest: 0.009 · change: 0.000
Affected products
- Beckhoff Twincat Extended Automation Runtime — versions 3.1
- Beckhoff Twincat Xar 3.1 — versions all
Weakness classification (CWE)
References
- cert.vde.com/en-us/advisories/vde-2020-037 (Third Party Advisory)
Frequently asked questions
- What is CVE-2020-12510?
- CVE-2020-12510 is a high-severity vulnerability in Beckhoff Twincat Extended Automation Runtime, classified under Incorrect Default Permissions. CVSS score: 7.3/10. Published 2020-11-19.
- How severe is CVE-2020-12510?
- High severity. CVSS v3 base score is 7.3 out of 10.