CODESYS: Control runtime system memory and integrity check vulnerabilities

Impact
The CODESYS Control runtime system enables embedded or PC-based devices to be a programmable industrial controller. Control programs (PLC application code) can access local or remote IOs, communication interfaces such as serial or sockets, or the file system.

Mitigation
To exploit these vulnerabilities, a successful login to the affected product is required. The online user management therefore protects from exploiting these security vulnerabilities.

CODESYS GmbH strongly recommends using the online user management. This not only prevents from downloading malicious code or boot application files, but also suppresses starting, stopping, debugging or other actions on a known working application that could potentially disrupt a machine or system. As of version 3.5.17.0, the online user management is enforced by default.

In addition, the CODESYS Development System and the CODESYS Control runtime system support optional signing and encryption of the application code loaded on the controller. This feature also prevents the loading and execution of untrusted or modified boot files. If the application code security policy is set to "Enforced Signing", a modified or untrusted application will be detected due to a missing signature and will not be loaded and executed.