What is null-session enumeration?

What is the meaning of null sessions?

A null session is an anonymized connection to an interprocess communication network service for Windows-based computers. This service allows named pipe connections, but attackers could use it to remotely access information about the system.

What is a SMB null session? Null sessions are unauthenticated sessions that do not belong to the Server Message Block (SMB), the core network protocol for Windows. It is a type communication that focuses mainly upon the provision of foundation for network file and print sharing services.

What is null session vulnerability, you ask?

Vulnerabilities In NULL Session Avail (SMB), a low-risk vulnerability, is the most commonly found on networks all over the globe. It was possible to log in using a null session. You can access information about remote hosts by using a NULL session (no login/password).

What ports should be blocked in order to prevent null session counteration?

By implementing the following security measures, you can prevent hackers from stealing null session connections: You can block NetBIOS from your Windows server by stopping these TCP ports passing through your personal firewall or network firewall: 139 (NetBIOS session services).