NoMachine before 5.3.27 and 6.x before 6.3.6 allows attackers to gain privileges via a Trojan horse wintab32.dll file located in the same directory as a .nxs file, as demonstrated by a scenario where the .nxs file and the DLL are in the current working directory, and the Trojan horse code is executed. (The directory could, in general, be on a local filesystem or a network share.).
NoMachine for Windows prior to version 6.15.1 and 7.5.2 suffer from local privilege escalation due to the lack of safe DLL loading. This vulnerability allows local non-privileged users to perform DLL Hijacking via any writable directory listed under the system path and ultimately execute code as NT AUTHORITY\SYSTEM.