------------------------------------------------------------------------ Seagate Media Server stored Cross-Site Scripting vulnerability ------------------------------------------------------------------------ Yorick Koster, September 2017 ------------------------------------------------------------------------ Abstract ------------------------------------------------------------------------ Seagate Personal Cloud is a consumer-grade Network-Attached Storage device (NAS). By default Seagate Media Server allows unauthenticated users to upload files to a public share. Once a file is uploaded it can also be downloaded again from the NAS. No restrictions are enforced on which file types a user can upload, any type of file can be uploaded including executable files & HTML files. File downloads are directly handled by Lighttpd and because of this file are processed based on its (MIME) type. An attacker can upload an HTML file and cause Lighttpd to treat the file as a regular web page. Consequently, uploading an HTML file can be used to execute a stored Cross-Site Scripting attack. ------------------------------------------------------------------------ Tested versions ------------------------------------------------------------------------ This issue was tested on a Seagate Personal Cloud model SRN21C running firmware versions 4.3.16.0 and 4.3.18.0. It is likely that other devices/models are also affected. ------------------------------------------------------------------------ Fix ------------------------------------------------------------------------ This vulnerability has been fixed in firmware version 4.3.18.4. ------------------------------------------------------------------------ Details ------------------------------------------------------------------------ https://sumofpwn.nl/advisory/2017/seagate-media-server-stored-cross-site-scripting-vulnerability.html
