 about performed attacks on systems. This information can often be publicly accessed and can contain information about hosts and infrastructure. Names, e-mail addresses, and other personal data of employees can be useful for phishing and brute-force attacks. This information is often available in publicly accessible source. A data breach is a confirmed incident where sensitive, confidential, or otherwise protected information has been accessed and/or disclosed in an unauthorized manner. Common data breach exposures include personal information such as credit card numbers, social security numbers, passwords as well as company information such as customer lists, production processes, and software source code. This data is often used for future attacks or blackmail. 208 Open Radio Access Network (O-RAN) Systems Architecture and Design The more information an attacker can discover, the easier it is to target a machine or service. Therefore it is important to leak as little information as possible about the hardware, operating system, and other software in use. For instance, it should not be possible for an attacker to use the load balancer to obtain sensitive information about the network. Internet searches, social engineering, research of public. Network reconnaissance In this phase ("active information gathering"), attackers map the structure and configuration of the wired and wireless side of the wireless network equipment and remainder compo- nents on the network. The wireless network side is visible for all devices that are located within the range of the network. An incorrect configuration could allow users to get unautho- rized access to the internal network. Many firewalls do not make it mandatory to change the default login details of the administrator account and are therefore vulnerable. Default admin credentials are always checked by intruders and should be disabled. Virtual private network (VPN) (IPSec) tunneling is used on O-RAN and other networking equipment such as Firewalls. It is required to use sec