An improper access control vulnerability in open-webui/open-webui v0.3.8 allows attackers to view and delete any files. The application does not verify whether the attacker is an administrator, allowing the attacker to directly call the GET /api/v1/files/ interface to retrieve information on all files uploaded by users, which includes the ID values. The attacker can then use the GET /api/v1/files/{file_id} interface to obtain information on any file and the DELETE /api/v1/files/{file_id} interface to delete any file.