A document-serving endpoint is a web path that returns stored files, images, or other documents to a user. Common examples include download handlers, preview pages, and image viewers. These endpoints often accept parameters that name a file, select a folder, or control access to shared content.
They matter because they sit at the boundary between private data and public access. If authorization is weak, an attacker may request documents they should not see, leading to file disclosure, backup exposure, or leakage of internal records. Defenders should treat every file-selection parameter as untrusted input, enforce server-side permission checks, and log requests for unusual file paths, identifiers, or shared-access tokens. Secure design also limits what the endpoint can read, so a mistake does not expose the entire document store.