The client (aka GalaxyClientService.exe) in GOG GALAXY through 2.0.41 (as of 12:58 AM Eastern, 9/26/21) allows local privilege escalation from any authenticated user to SYSTEM by instructing the Windows service to execute arbitrary commands. This occurs because the attacker can inject a DLL into GalaxyClient.exe, defeating the TCP-based “trusted client” protection mechanism.
Source: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-24574
Reference (s):
- https://github.com/jtesta/gog_galaxy_client_service_poc
- https://github.com/jtesta/gog_galaxy_client_service_poc/issues/1#issuecomment-926932218
- https://www.gog.com/galaxy
- https://www.positronsecurity.com/blog/2020-08-13-gog-galaxy_client-local-privilege-escalation_deuce/