A vulnerability (CVE-2022-2967) has been discovered in Prosys OPC UA applications that enables an attacker to gain unauthorized access to Prosys OPC UA Simulation Server or Modbus Server.

The exploit has been evaluated with CVSS Base Score 6.5 and Vector String CVSS:3.0/AV:L/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:H.

Details

The exploit enables a local privileged user to obtain the passwords of the users after they have been entered in the user interface of the OPC UA server applications and use them to authenticate respectively via the OPC UA interface.

The vulnerability was discovered by researchers at the Purdue University and it was reported by CISA as ICSA-22-349-01

Prosys OPC UA products affected

The vulnerability affects directly:

• Prosys OPC UA Simulation Server 5.3.0 and earlier
• Prosys OPC UA Modbus Server 1.4.18 and earlier

Fixed products

The issue has been fixed in Simulation Server 5.4.0 and Modbus Server 1.4.20 and we encourage everyone to update to these versions.

Avoiding the issue in existing products

The vulnerability occurs only when passwords are edited in the applications. If the applications are restarted after editing passwords, the exploit will not succeed, so that is a working mitigation.

It is also very important to ensure the physical security of the computers that are run the OPC UA applications. Since this issue is only locally exploitable, proper physical securty will mitigate the vulnerability.

More security information

You will find the currently announced security issues in Prosys OPC products from the blog under the #Security tag.

You might also like to read about the OPC UA Security Process of the OPC Foundation.