Serviio PRO 1.8 DLNA Media Streaming Server Local Privilege Escalation

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Serviio PRO 1.8 DLNA Media Streaming Server Local Privilege Escalation  
  
  
Vendor: Petr Nejedly | Six Lines Ltd  
Product web page: http://www.serviio.org  
Affected version: 1.8.0.0 PRO  
  
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.  
  
Desc: 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 useras 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.  
  
  
Tested on: Microsoft Windows 7 Professional SP1 (EN)  
Microsoft Windows 7 Ultimate SP1 (EN)  
  
  
Vulnerability discovered by Gjoko 'LiquidWorm' Krstic  
@zeroscience  
  
  
Advisory ID: ZSL-2017-5405  
Advisory URL: http://www.zeroscience.mk/en/vulnerability/ZSL-2017-5405.php  
  
SSD Advisory: https://blogs.securiteam.com/index.php/archives/3094  
  
  
12.12.2016  
  
---  
  
  
C:\>sc qc Serviio  
[SC] QueryServiceConfig SUCCESS  
  
SERVICE_NAME: Serviio  
TYPE : 110 WIN32_OWN_PROCESS (interactive)  
START_TYPE : 2 AUTO_START  
ERROR_CONTROL : 1 NORMAL  
BINARY_PATH_NAME : C:\Program Files\Serviio\bin\ServiioService.exe  
LOAD_ORDER_GROUP :  
TAG : 0  
DISPLAY_NAME : Serviio  
DEPENDENCIES : HTTP  
SERVICE_START_NAME : LocalSystem  
  
C:\>icacls "C:\Program Files\Serviio\bin\ServiioService.exe"  
C:\Program Files\Serviio\bin\ServiioService.exe BUILTIN\Users:(I)(F)  
NT AUTHORITY\SYSTEM:(I)(F)  
BUILTIN\Administrators:(I)(F)  
  
Successfully processed 1 files; Failed processing 0 files  
  
C:\>  
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