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.

CVSS v3.0 7.3 HIGH
CVSS v2.0 6.0 MEDIUM

7.3^/10

CVSS v3.0 : HIGH

Vector :

Exploitability : 1.3 / Impact : 5.9

Attack Vector LOCAL

Attack Complexity LOW

Privileges Required LOW

User Interaction REQUIRED

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

6.0^/10

CVSS v2.0 : MEDIUM

Vector : AV:N/AC:M/Au:S/C:P/I:P/A:P

Exploitability : 6.8 / Impact : 6.4

Access Vector NETWORK

Access Complexity MEDIUM

Authentication SINGLE

Confidentiality Impact PARTIAL

Integrity Impact PARTIAL

Availability Impact PARTIAL

References

Link	Resource
https://cert.vde.com/en-us/advisories/vde-2020-037	Third Party Advisory

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Configurations

Configuration 1 (hide)

cpe:2.3:a:beckhoff:twincat_extended_automation_runtime:3.1:*:*:*:*:*:*:*

Information

Published : 2020-11-19 10:15

Updated : 2020-12-03 08:47

NVD link : CVE-2020-12510

Mitre link : CVE-2020-12510

JSON object : View

CWE

CWE-276

Incorrect Default Permissions

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Products Affected

beckhoff

twincat_extended_automation_runtime

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