SYSTEM file creation via junction race

TOCTOU race in the TeamViewer service in Full Client and Host before 15.69 on Windows allows local users to create files as SYSTEM. The service validates a directory and later uses it without preventing a low-privileged user from replacing the path with a junction, so the privileged file operation follows an attacker-controlled target. Exploitation requires local low-privileged code execution and can create arbitrary files as SYSTEM, with the reported consequence bounded to denial of service.