5.4 Wireless Network Security

Wireless networks offer convenience but come with unique security challenges. Signals can be intercepted beyond intended areas, and rogue access points pose threats. Understanding these risks is crucial for implementing effective security measures.

Authentication and encryption are key defenses for wireless networks. WPA2, 802.1X authentication, and VPNs provide strong protection against unauthorized access and data breaches. Regular security audits help maintain a robust wireless security posture.

Wireless Network Security Fundamentals

Security challenges of wireless networks

• Signal propagation and accessibility enable wireless signals to penetrate walls and extend beyond intended areas making them susceptible to interception by unauthorized users within range
• Rogue access points are unauthorized access points connected to the network without permission which can be used to gain access to the internal network and resources
• Evil twin attacks involve an attacker setting up a malicious access point with the same SSID as a legitimate one causing users to unknowingly connect to the malicious access point and expose their data
• Wardriving and unauthorized access occur when attackers drive around to locate and exploit unsecured wireless networks allowing them to access unsecured networks without authorization and compromise data

Authentication and encryption for wireless

• Wi-Fi Protected Access (WPA) and WPA2 are security protocols that provide strong encryption and authentication using Advanced Encryption Standard (AES) for data confidentiality and employing Pre-Shared Key (PSK) or 802.1X authentication for access control
• 802.1X authentication is a port-based authentication method using a RADIUS server that supports various Extensible Authentication Protocol (EAP) methods to ensure only authorized users can connect to the wireless network
• Virtual Private Networks (VPNs) establish secure, encrypted tunnels over the wireless network to protect data transmitted between wireless clients and the network and prevent eavesdropping and unauthorized access to sensitive information

Wireless Network Security Configuration and Auditing

Securing wireless access points

• Change default administrator credentials by replacing default usernames and passwords with strong, unique credentials to prevent attackers from accessing the access point using known defaults
• Disable unnecessary services and features like telnet, SSH, and web management if not required to reduce the attack surface and potential vulnerabilities
• Enable MAC address filtering to restrict access to the wireless network based on client MAC addresses allowing only authorized devices to connect to the network
• Implement strong encryption and authentication settings using WPA2 with AES encryption and a strong PSK to ensure data confidentiality and prevent unauthorized access

Wireless network security audits

1. Perform regular wireless network scans using tools like Aircrack-ng, Kismet, or inSSIDer to detect rogue access points and identify unauthorized devices connected to the wireless network
2. Assess signal strength and coverage to ensure wireless signals do not extend beyond the intended coverage area and adjust access point placement and signal strength to minimize signal leakage
3. Test authentication and encryption settings by verifying that strong authentication methods and encryption protocols are in use and attempting to connect to the network using weak or default credentials
4. Review access point configurations to check for misconfigurations, outdated firmware, and security vulnerabilities and ensure access points are hardened and adhere to security best practices