ZKTeco BioTime 8.5.5 through 9.x before 9.0.1 (20240617.19506) allows authenticated attackers to create or overwrite arbitrary files on the server via crafted requests to /base/sftpsetting/ endpoints that abuse a path traversal issue in the Username field and a lack of input sanitization on the SSH Key field. Overwriting specific files may lead to arbitrary code execution as NT AUTHORITY\SYSTEM.