ecshop一处验证码绕过逻辑漏洞

虽然验证码进行了加密，但是逻辑上还有点问题

问题出在

../includes/cls_captcha.php

通过验证函数可以看到直接返回，并没有对验证失败进行处理

code 区域

function check_word($word)      {          $recorded = isset($_SESSION[$this->session_word]) ? base64_decode($_SESSION[$this->session_word]) : '';          $given    = $this->encrypts_word(strtoupper($word)); //MD5加密处理            return (preg_match("/$given/", $recorded)); //验证规则      }

也就是说如果登陆失败的时候没有对验证码SESSION置空的话，就可以在这次请求中反复尝试进行破解。

下面代码可以看到并没有对验证错误的时候进行处理

../ecshop/admin/privilege.php

code 区域

if (intval($_CFG['captcha']) & CAPTCHA_ADMIN)      {          include_once(ROOT_PATH . 'includes/cls_captcha.php');            /* 检查验证码是否正确 */          $validator = new captcha();          if (!empty($_POST['captcha']) && !$validator->check_word($_POST['captcha']))          {              sys_msg($_LANG['captcha_error'], 1);          }      }      $_POST['username'] = isset($_POST['username']) ? trim($_POST['username']) : '';      $_POST['password'] = isset($_POST['password']) ? trim($_POST['password']) : '';      $sql="SELECT `ec_salt` FROM ". $ecs->table('admin_user') ."WHERE user_name = '" . $_POST['username']."'";     echo $sql."<br/>";      $ec_salt =$db->getOne($sql);      if(!empty($ec_salt))      {           /* 检查密码是否正确 */           $sql = "SELECT user_id, user_name, password, last_login, action_list, last_login,suppliers_id,ec_salt".              " FROM " . $ecs->table('admin_user') .              " WHERE user_name = '" . $_POST['username']. "' AND password = '" . md5(md5($_POST['password']).$ec_salt) . "'";      }      else      {           /* 检查密码是否正确 */           $sql = "SELECT user_id, user_name, password, last_login, action_list, last_login,suppliers_id,ec_salt".              " FROM " . $ecs->table('admin_user') .              " WHERE user_name = '" . $_POST['username']. "' AND password = '" . md5($_POST['password']) . "'";      }      $row = $db->getRow($sql);        if ($row)      {....}