CODESYS Development System Local Privilege Escalation Vulnerability via TOCTOU Race Condition

A local privilege escalation vulnerability has been identified in the CODESYS Development System, specifically in versions prior to 3.5.22.20. During administrative installations, the application extracts files to a temporary directory with improper default permissions. This flaw allows low-privileged local attackers to exploit a Time-of-Check to Time-of-Use (TOCTOU) race condition, replacing verified installation files with malicious ones before they are installed. The vulnerability takes advantage of a practical time window, leading to unauthorized privilege escalation.

Impact

Exploitation of this vulnerability allows low-privileged local attackers to escalate privileges, executing actions with administrative rights. This could involve installing malicious files that compromise the underlying operating system.

Remediation

Users are advised to update the CODESYS Development System to version 3.5.22.20. The update is available through the CODESYS Installer, the CODESYS Store, or the CODESYS Update area.