The network attack surface is the totality of all vulnerabilities in connected hardware and software that are accessible to unauthenticated users.
Every point of network interaction is a part of the network attack surface. Hackers, industrial spies and malware such as worms and advanced persistent threats (APTs) target these points for potential entry to a network they wish to disrupt or capture data from.
A network’s attack surface is most often exploited through remote access and intrusion but Wi-Fi and even local area networks (LANs) must also be considered in a complete view of the attack surface. Technologies that rely on tunneling such as virtual private networks (VPNs), peer-to-peer (P2P) and Teredo constitute a threat to networks, as they circumvent intrusion prevention and other security measures.
The network attack surface can be reduced by closing unnecessary ports and limiting resources available to untrusted users and the Internet in general with techniques like MAC address filtering. Any forms of tunneling should be limited to those that are necessary, and access should be stringently controlled. Limiting some network attack vectors can also limit exposure of existing software vulnerabilities by blocking access to them.
A complete attack surface analysis is crucial to proper set up of breach detection systems (BDS), firewall, intrusion prevention systems, data policy and other security measures. Many attack approaches exploit a combination of attack surface types to gain access to desired resources.