What network security technique is a reverse shell designed to overcome? How does it achieve this?

A reverse shell is designed to overcome network firewalls.

Here's how it works:

1. Firewalls are security systems that monitor and control incoming and outgoing network traffic based on predetermined security rules. They typically block unauthorized access from the internet to an internal network.

2. A reverse shell works by initiating the connection from the target machine (the one being attacked) to the attacker's machine, instead of the other way around. This is the "reverse" part of a reverse shell.

3. Because the connection is initiated from the inside of the network, it can bypass the firewall's rules against unsolicited incoming connections.

4. Once the connection is established, the attacker can send commands to the target machine and receive the output of those commands, effectively giving them control over the target machine.

5. This technique is often used in combination with other techniques to gain initial access to the target machine, such as phishing or exploiting a software vulnerability.