The Wertheim SafeController Software, AssemblyVersion 6.15.8328.28014, contains insufficient server-side file type validation in the /safe/contract/uploadcustomdocuments endpoint. The application validates uploaded files based on the user-controlled HTTP Content-Type value and accepts the upload if this value contains an allowed string such as pdf, jpeg, tiff, or png. An authenticated attacker with any role or permission level can spoof the Content-Type value and upload arbitrary file content.