RealNetworks RealPlayer/RealOne Player/Helix Player Remote Heap Overflow
	by Piotr Bania <bania.piotr@gmail.com>
	http://www.piotrbania.com

	Original location: 	http://www.piotrbania.com/all/adv/real-ram-adv.txt
	

	Severity: 		Critical - Remote code execution.

	Software affected: 	(WINDOWS)
				RealPlayer 10.5 (6.0.12.1040 - 1059)
				RealPlayer 10
				RealOne Player v2
				RealOne Player v1
				RealPlayer 8
				RealPlayer Enterprise

				(MAC)
				Mac RealPlayer 10 (10.0.0.305 - 331)
				Mac RealOne Player

				(LINUX)
				Linux RealPlayer 10 (10.0.0 - 3)
				Helix Player (10.0.0 - 3)




	
	I.  BACKGROUND

	Real*Player* is surely one of the most popular media players nowadays 
	with over a 200 million of users worldwide. 

	II. DESCRIPTION

	The problem exists when RealPlayer parses special crafted .ram file. 
        Normaly .ram file looks like that:

	--CUT--
	http://www.host.com/media/getmetafile.ram?pinfo=fid:2663610|  	\
	bw:MULTI|mt:ro|mft:metafile|cr:1|refsite:276
	--CUT--

	this causes RealPlayer to contact "www.host.com" and try to download
	and play selected clip. The problem exists when host string is too long,
	like here:

	--CUT--
	http://www.ABC.ABC.ABC.ABC.ABC.ABC.ABC.ABC.ABC.<...>. 		\
	.org/media/getmetafile.ram?pinfo=fid:2663610|bw:MULTI|mt:ro| 	\
	mft:metafile|cr:1|refsite:276
	--CUT--

	While parsing such crafted .ram file heap memory is being corrupted at 
	multiple locations, for example:

	FIRST HEAP CORRUPTION:

	----// SNIP SNIP //-------------------------------------------------
	(MODULE PNEN3260)
	01053089   76 0D            JBE SHORT pnen3260.01053098
	0105308B   8B53 15          MOV EDX,DWORD PTR DS:[EBX+15]
	0105308E   890496           MOV DWORD PTR DS:[ESI+EDX*4],EAX  <--- 
	01053091   8B43 15          MOV EAX,DWORD PTR DS:[EBX+15]
	01053094   40               INC EAX
	01053095   8943 15          MOV DWORD PTR DS:[EBX+15],EAX
	----// SNIP SNIP //-------------------------------------------------

	THE FINAL HEAP OVERWRITE:

	----// SNIP SNIP //-------------------------------------------------
	(MODULE PNCRT - PNCRT!strncpy+0x8b)
	60A2FA59   8917             MOV DWORD PTR DS:[EDI],EDX
	60A2FA5B   83C7 04          ADD EDI,4
	60A2FA5E   49               DEC ECX
	60A2FA5F  ^74 AF            JE SHORT PNCRT.60A2FA10
	----// SNIP SNIP //-------------------------------------------------

	
	In the following code EDI points to heap location, and EDX contains read
	bytes. Instruction at 60A2Fa59 writes value of EDX register into the 
	location where EDI points (heap memory), this causes a heap memory 
        corruption.


	III. IMPACT

	Successful exploitation may allow the attacker to run arbitrary code in 
	context of user running RealPlayer.

	IV.  VENDOR RESPONSE

	I would like to acknowledge the cooperation and responsiveness of the people 
	at RealNetworks. Security patches are available at http://www.real.com.