Serviio PRO 1.8 DLNA Media Streaming Server Local Privilege Escalation

Title: Serviio PRO 1.8 DLNA Media Streaming Server Local Privilege Escalation
Advisory ID: ZSL-2017-5405
Type: Local
Impact: Privilege Escalation
Risk: (3/5)
Release Date: 03.05.2017
Summary
Serviio is a free media server. It allows you to stream your media files (music, video or images) to renderer devices (e.g. a TV set, Bluray player, games console or mobile phone) on your connected home network.
Description
The application suffers from an unquoted search path issue impacting the service 'Serviio' for Windows deployed as part of Serviio DLNA server solution. This could potentially allow an authorized but non-privileged local user to execute arbitrary code with elevated privileges on the system. A successful attempt would require the local user to be able to insert their code in the system root path undetected by the OS or other security applications where it could potentially be executed during application startup or reboot. If successful, the local user’s code would execute with the elevated privileges of the application.

Serviio also suffers from improper permissions which can be used by a simple authenticated user that can change the executable file with a binary of choice. The vulnerability exist due to the improper permissions, with the 'F' flag (Full) for 'Users' group, for the Serviio directory and its sub-directories.
Vendor
Petr Nejedly | Six Lines Ltd - http://www.serviio.org
Affected Version
1.8.0.0 PRO
1.7.1
1.7.0
1.6.1
Tested On
Restlet-Framework/2.2
Windows 7, UPnP/1.0 DLNADOC/1.50, Serviio/1.8
Mac OS X, UPnP/1.0 DLNADOC/1.50, Serviio/1.8
Linux, UPnP/1.0 DLNADOC/1.50, Serviio/1.8
Vendor Status
[12.12.2016] Vulnerability discovered.
[02.05.2017] Vendor communicated via Beyond Security's SecuriTeam Secure Disclosure program.
PoC
serviio_eop.txt
Credits
Vulnerability discovered by Gjoko Krstic - <gjoko@zeroscience.mk>
References
[1] https://blogs.securiteam.com/index.php/archives/3094
[2] https://www.exploit-db.com/exploits/41959/
[3] https://packetstormsecurity.com/files/142384
[4] https://cxsecurity.com/issue/WLB-2017050019
Changelog
[03.05.2017] - Initial release
[05.05.2017] - Added reference [2], [3] and [4]
Contact
Zero Science Lab

Web: http://www.zeroscience.mk
e-mail: lab@zeroscience.mk