ICS Advisories

Risk evaluation

A vulnerability in the CODESYS Control runtime system's CmpVisuServer component allows attackers to cause a denial-of-service (DoS) by sending special request to the CODESYS Web- or remote Target Visu. The issue is triggered by an internal read access using a pointer of wrong type. Only CODESYS Control runtime systems and PLCs based on the CODESYS Runtime Toolkit that include the CmpVisuServer component are impacted. In the case of CODESYS Web Visu, the vulnerability can only be exploited if the web server is running. When the web server starts depends on the startup configuration: By default, it is only running if the PLC executes application code that includes a visualization.

Mitigation summary

Update the following products to version 3.5.21.40. * CODESYS Control RTE (SL) * CODESYS Control RTE (for Beckhoff CX) SL * CODESYS Control Win (SL) * CODESYS HMI (SL) * CODESYS Remote Target Visu * CODESYS Runtime Toolkit The CODESYS Development System and the products available as CODESYS add-ons can be downloaded and installed directly with the CODESYS Installer or be downloaded from the CODESYS Store. Alternatively, as well as for all other products, you will find further information on obtaining the software update in the CODESYS Update area https://www.codesys.com/download/.