title: A potentially dangerous Request.QueryString value was detected from the client
body: <p>I'm using WebForm</p>
  
  <p>I'm doing a Security Testing to my site but when I try to pass through url a QueryString like:</p>
  
  <blockquote>
    <p>'"-->netsparker(0x00286A) 
    mysite/Error/PageNotFound.aspx?aspxerrorpath=%27%22--%3E%3C/style%3E%3C/script%3E%3Cscript%3Enetsparker(0x0030C5)%3C/script%3E</p>
  </blockquote>
  
  <p>I got Server Error in '/' Application.</p>
  
  <blockquote>
    <p>A potentially dangerous Request.QueryString value was detected from
    the client  A potentially dangerous Request.Path value was detected from the client (>).</p>
  </blockquote>
  
  <p>I have in the web.config</p>
  
  <pre><code>&lt;httpRuntime  enableVersionHeader="false"/&gt;
  &lt;customErrors mode="On"  defaultRedirect="~/Error/GeneralError.aspx"&gt;
    &lt;error statusCode="404" redirect="~/Error/PageNotFound.aspx" /&gt;
    &lt;error statusCode="403" redirect="~/Error/GeneralError.aspx" /&gt;    
    &lt;error statusCode="500" redirect="~/Error/GeneralError.aspx" /&gt;      
  &lt;/customErrors&gt;
  
      ..................
  
  &lt;pages controlRenderingCompatibilityVersion="4.0" viewStateEncryptionMode="Always"&gt;
  </code></pre>
  
  <p>Any idea how can I correct that?</p>