File sharing has moved onto HTTP, and three forms dominate. Simple HTTP file servers (from a language's built-in server to purpose-built apps) expose directories for download and sometimes upload. WebDAV extends HTTP with read-write verbs, turning a web server into a mountable, writable filesystem. And managed file transfer (MFT) products provide governed business-to-business file exchange through web portals and APIs. Each has a distinct surface: listing and traversal on plain file servers, upload-to-execution and verb abuse on WebDAV, and on MFT the authentication bypasses and injection flaws that have driven some of the largest mass-exploitation campaigns.
# fingerprint what is serving files over HTTP
curl -sI http://<target>/ # Server header, allowed methods
curl -s -X OPTIONS http://<target>/ -i | grep -i allow # WebDAV verbs?
Subtopics#
- HTTP file servers: directory listing, traversal, and upload-to-RCE.
- WebDAV: the read-write HTTP extension.
- Managed file transfer: the MFT appliances and their exploits.