An issue was discovered in BeyondTrust Privilege Management for Windows through 5.6. When specifying a program to elevate, it can typically be found within the Program Files (x86) folder and therefore uses the %ProgramFiles(x86)% environment variable. However, when this same policy gets pushed to a 32bit machine, this environment variable does not exist.

Therefore, since the standard user can create a user level environment variable, they can repoint this variable to any folder the user has full control of. Then, the folder structure can be created in such a way that a rule matches and arbitrary code runs elevated.