title: How to fix Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS) with error message?
body: <p>We use web control adapter in our login page. Recently we run VeraCode on our web application. In following function, we got CWE80, Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS), on the line </p>
  
  <pre><code>rev.ErrorMessage = msg;
  </code></pre>
  
  <p>Following is the function in the WebControlAdapterExtender class.</p>
  
  <pre><code>static public void WriteRegularExpressionValidator(HtmlTextWriter writer, RegularExpressionValidator rev, string className, string controlToValidate, string msg, string expression)
          {
              if (rev != null)
              {
                  rev.CssClass = className;
                  rev.ControlToValidate = controlToValidate;
                  rev.ErrorMessage = msg;
                  rev.ValidationExpression = expression;
                  rev.RenderControl(writer);
              }
          }
  </code></pre>
  
  <p>Does anyone have any suggestion how to fix this?</p>