Improve potential XSS attack #57
Description
It is possible to circumvent the IDS filter using the following vectors:
<p onmouseover=-a() ></p>
<p onmouseover=(a()) ></p>
<p onmouseover=;a() ></p>
<p onmouseover=!a() ></p>
Other types of events can also be use used for the attack (e.g. "onClick").
The vulnerability is allowed because the filter requires an alphanumeric character (and the symbols "_" "$") after an event followed by the "=" symbol in order to flag the input as an attack and increase the impact. By adding a symbol that does not break the JavaScript syntax (such as the "-" or the parenthesis "()" ) just after the "=" character permits an adversary to bypass this pattern check. Rules 71, 27, 2 and 65 are related to this insufficient pattern match. It is recommended to extend these regular expressions in order to also include the symbols in the accepted pattern.
The issue is clone of PHPIDS/PHPIDS#74