1E Client installer can perform arbitrary file deletion on protected files.  

A non-privileged user could provide a symbolic link or Windows junction to point to a protected directory in the installer that the 1E Client would then clear on service startup. A hotfix is available Q23092 that forces the 1E Client to check for a symbolic link or junction and if it finds one refuses to use that path and instead creates a path involving a random GUID.

1E Client installer can perform arbitrary file deletion on protected files.  

A non-privileged user could provide a symbolic link or Windows junction to point to a protected directory in the installer that the 1E Client would then clear on service startup. 

A hotfix is available from the 1E support portal that forces the 1E Client to check for a symbolic link or junction and if it finds one refuses to use that path and instead creates a path involving a random GUID.

for v8.1 use hotfix Q23097
for v8.4 use hotfix Q23105
for v9.0 use hotfix Q23115

for SaaS customers, use 1EClient v23.7 plus hotfix Q23121