Riot Games League of Legends - Insecure File Permissions Privilege Escalation

2016-06-10T00:00:00
ID EDB-ID:39916
Type exploitdb
Reporter Cyril Vallicari
Modified 2016-06-10T00:00:00

Description

Riot Games League of Legends - Insecure File Permissions Privilege Escalation. Local exploit for windows platform

                                        
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# Exploit Title: Riot Games League of Legends Insecure File Permissions Privilege Escalation
# Date: 03/06/16
# Exploit Author: Cyril Vallicari (i give credit also to Vincent Yiu he
probably found this too)
# Vendor Homepage: http://www.leagueoflegends.com
# Version : LeagueofLegends_EUW_Installer_2016_05_13.exe (last version) and LeagueofLegends_EUW_Installer_9_15_2014.exe (an old one)
# Tested on: Windows 7 Professional x64 fully updated. But it should work on all windows system

Description:

The League of Legends Folder is installed with insecure file
permissions. It was found that all folder and most file permissions were
incorrectly configured during installation. It was possible to replace most
binaries.
This can be used to get a horizontal and vertical privilege escalation.

POC :

C:\Users\Utilisateur>icacls "C:\Riot Games\League of Legends"
C:\Riot Games\League of Legends BUILTIN\Administrateurs:(I)(F)
                                BUILTIN\Administrateurs:(I)(OI)(CI)(IO)(F)
                                AUTORITE NT\Système:(I)(F)
                                AUTORITE NT\Système:(I)(OI)(CI)(IO)(F)
                                BUILTIN\Utilisateurs:(I)(OI)(CI)(RX)
                                AUTORITE NT\Utilisateurs authentifiés:(I)(M)
                                AUTORITE NT\Utilisateurs
authentifiés:(I)(OI)(CI)(IO)(M)


POC video : https://www.youtube.com/watch?v=_t1kvXBGV2E


Additional Notes :

"Based on our assessment, we feel that the severity and risk related to
this issue is low. We are going to mark this as a won't fix as we're
planning on will be taking this functionality offline soon with our new
league client."

"we determined that there are some design choices regarding the game client
install location and default permissions that prevent us from changing the
current behavior."

I've try to explain that file permissions aren't a functionality that you
take offline or design choices, without success. Sorry guys you will have
to patch this manually..

Related report :
 https://www.exploit-db.com/exploits/39903/

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