A local user with low privileges may be able to influence the behavior of a privileged system service by manipulating configuration or application-related files located in user-writable areas of the filesystem. The affected service processes data from locations that are not sufficiently protected against modification by low-privileged users. As the service runs with elevated privileges, successful exploitation may result in a local privilege escalation.

A local user with low privileges may be able to influence the behavior of a privileged system service by manipulating configuration or application-related files located in user-writable areas of the filesystem. The affected service processes data from locations that are not sufficiently protected against modification by low-privileged users. As the service runs with elevated privileges, successful exploitation may result in a local privilege escalation.

This advisory addresses security issues in PLCnext firmware versions prior to 2026.0.3 that are related to APP handling and the processing of configuration files. The identified vulnerabilities affect APP installation authenticity as well as the handling of configuration data in writable directories. Successful exploitation may allow authenticated attackers with different privilege levels to compromise integrity, availability, and system security of affected PLCnext Control. Both issues are resolved starting with PLCnext firmware version 2026.0.3.