UPDATE: Confirmed: This has been fixed on the iOS 8.0.2 update.
Using PUT/POST to upload file(s) over HTTP seems to get stuc
This was a bug in iOS 8.0.0 and was fixed in 8.0.2. The file body is not included in the request payload, but Content-Length is set as if it is.
Content-Length
See blog post File uploads appear to be broken in Safari on iOS 8.