Working with bind and reverse shells

Bind shells are commonly used by penetration testers to logically set up a service port in a listening state on a targeted system while binding the listening service port to a native shell such as Bourne Again Shell (Bash) on Linux or Command Prompt on Windows; this is commonly referred to as a listener. Once the penetration tester initiates a connection to the listener and a session is established, the penetration tester will gain access to the targeted system’s native shell, whether it’s Bash on Linux or Command Prompt on a Windows-based system.

Imagine your target is a vulnerable server on the internet with a public IP address, while your attacker machine, such as Kali Linux, is behind a router or firewall with network address translation (NAT) enabled. If there is a firewall between the source and destination, some firewalls are usually configured to allow outbound traffic from their internal network to the internet, but not...