League of Legends Screensaver – Unquoted Service Path Privilege Escalation

  • 作者: Vincent Yiu
    日期: 2016-06-07
  • 类别:
    平台:
  • 来源:https://www.exploit-db.com/exploits/39902/
  • # Exploit Title: League of Legends Screensaver Unquoted Service Paths
    Conditional Privilege Escalation.
    # CVE-ID: NA
    # Date: 13/04/2016
    # Exploit Author: Vincent Yiu
    # Contact: vysec.private@gmail.com
    # Vendor Homepage: http://www.leagueoflegends.com
    # Software Link: screensaver.euw.leagueoflegends.com/en_US
    # Version: MD5 Hash: 0C1B02079CA8BF850D59DD870BC09963
    # Tested on: Windows 7 Professional x64 fully updated.
    
    1. Description:
    
    The League of Legends installer would install the League of Legends
    screensaver along with a service. The service would be called
    'lolscreensaver'. This particular service was misconfigured such that
    the service binary path was unquoted. When the screensaver is
    installed to 'C:\Riot Games', the issue is not exploitable. However,
    during the installation process, users are able to specify a directory
    to install to. When a user chooses to install this to say an external
    drive, this becomes exploitable.
    
    This was reported to Riot Games and has been rectified in the latest version.
    
    2. Proof
    http://i.imgur.com/S2fuUKa.png
    
    
    3. Exploit:
    
    Simply run 'sc qc lolscreensaver' and check for unquoted service path.
    If the path is unquoted, then check the permissions of each directory
    using space as a token.
    
    Eg. D:\My Games\Hidden Files\Super Secure\Riot Games\service\service.exe
    
    Do icacls on D:\, 'D:\My Games\', 'D:\My Games\Hidden Files\', 'D:\My
    Games\Hidden Files\Super Secure\'. If you are able to write files to
    any of these directories, it is exploitable.
    
    If 'D:\My Games\' is writable, to exploit this issue, place a binary
    to run as SYSTEM into the folder and named as 'Hidden.exe".
    
    
    This is released on exploit-db as a means to make users aware. There was no way to automatically install a patch or update to fix this issue. It is recommended that the screensaver is uninstalled and redownloaded from the official website where this issue is now resolved.