ecshop /api/client/api.php、/api/client/includes/lib_api.php SQL Injection Vul

catalog

. 漏洞描述
. 漏洞触发条件
. 漏洞影响范围
. 漏洞代码分析
. 防御方法
. 攻防思考

1. 漏洞描述

ECShop存在一个盲注漏洞，问题存在于/api/client/api.php文件中，提交特制的恶意POST请求可进行SQL注入攻击，可获得敏感信息或操作数据库

http://sebug.net/vuldb/ssvid-21007

2. 漏洞触发条件

. /api/client/api.php存在未过滤漏洞
. 服务器magic_quote_gpc = off
//magic_quote_gpc特性已自 PHP 5.3.0 起废弃并将自 PHP 5.4.0 起移除，即默认情况下，magic_quote_gpc = Off

0x1: POC

http://localhost/ecshop2.7.2/api/client/api.php?Action=UserLogin
POST: UserId=%%20or%20user_id=%

Relevant Link:

http://php.net/manual/zh/info.configuration.php

3. 漏洞影响范围
4. 漏洞代码分析

/api/client/api.php

<?php

define('IN_ECS', true);

include_once './includes/init.php';

//分发处理POST数据
dispatch($_POST);
?>

/api/client/includes/lib_api.php

function dispatch($post)
{
    // 分发器数组
    $func_arr = array('GetDomain', 'UserLogin', 'AddCategory', 'AddBrand', 'AddGoods', 'GetCategory', 'GetBrand', 'GetGoods', 'DeleteBrand', 'DeleteCategory', 'DeleteGoods', 'EditBrand', 'EditCategory', 'EditGoods');
    //当$_POST['Action'] == 'UserLogin'的时候调用API_UserLogin
    if(in_array($post['Action'], $func_arr) && function_exists('API_'.$post['Action']))
    {
        return call_user_func('API_'.$post['Action'], $post);
    }
    else
    {
        API_Error();
    }
}

/api/client/includes/lib_api.php

function API_UserLogin($post)
{
    $post['username'] = isset($post['UserId']) ? trim($post['UserId']) : '';
    $post['password'] = isset($post['Password']) ? strtolower(trim($post['Password'])) : '';

    /* 检查密码是否正确 */
    //$post['username']未进行过滤，造成盲注漏洞，参数是直接从原始$_POST获取的，未进行任何预处理，不受内核过滤影响
    $sql = "SELECT user_id, user_name, password, action_list, last_login".
    " FROM " . $GLOBALS['ecs']->table('admin_user') .
    " WHERE user_name = '" . $post['username']. "'";

    $row = $GLOBALS['db']->getRow($sql);
    ..

Relevant Link:

http://www.wooyun.org/bugs/wooyun-2010-02969

5. 防御方法

/api/client/includes/lib_api.php

function API_UserLogin($post)
{
    /* SQL注入过滤 */
    if (get_magic_quotes_gpc())
    {
        $post['UserId'] = $post['UserId']
    }
    else
    {
        $post['UserId'] = addslashes($post['UserId']);
    }
    /* */
    $post['username'] = isset($post['UserId']) ? trim($post['UserId']) : '';
    ..

Relevant Link:

http://www.topit.cn/ecshop-tutorial/ecshop_mangzhu_bug_for_ecshop_v2.7.2-195.html

6. 攻防思考

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