Jeffrey Dingle, CPP

Wireless is a great thing. Wireless anything. The ability to connect gadgets without wires is a great step forward in electronic technology. What started as simple wireless controls to my TV expanded to my ceiling fan, and now my gas fireplace has a wireless remote control - I just push a button and the fire burns, push another button and the fire puts itself out.

As wireless moved into the world of security, we recognized the benefit in systems installation and operation. The ability to install systems without having to pull wires is a tremendous advantage. But as we look at security systems, security of the system must be addressed. After all, what good is an unsecured security system? A recent news article reports that the new U.K. passports have already been compromised. The compromise involves using electronic “sniffer” hardware to read personal information from the RFID-based passport. A design requirement of the passport was to be “machine readable” from a short distance, and this requirement creates an exploitable weakness.

Wireless Weaknesses

Wireless systems, while attractive from an installation and operational standpoint, have a security weakness. Wireless systems are inherently less secure simply because they are vulnerable to interception or corruption as signals get transmitted through the air. In some cases, interception is not an issue, and security might not matter. If a Wireless Access Point (WAP) is used, certain security requirements should be utilized. First, change the default Server Set ID (SSID); access points come with a default-shared key called an SSID that is common among all users of that access point. It is broadcast to everyone within range of the access point. Be sure to change this SSID from the default setting, so that hackers have less information about the equipment and its setup. Replace it with a meaningful name (e.g., Third_floor_Lab, or Security_main_room). Do not allow connections using a blank SSID or an SSID set to ANY or any, and note that SSIDs are case sensitive.

It is also important to change the default configuration password. All wireless access points come with a default password to access the configuration program. Default passwords for WAP configuration are easily found online. Keeping a default password could allow someone to easily change the configuration and even deny access into your own system. Change the default password and use a strong password. Equally important is allowing only Wired Equivalent Privacy (WEP) connections. WEP is a standard for encrypting wireless data. Set WEP to 128-bit if possible (the higher, the better). Without the appropriate WEP key, it is less likely to enter a wireless access point. If the system does not have the WEP enabled, everything sent is accessible by unauthorized individuals.

Four Kinds of Attacks

Wireless systems are vulnerable to attacks in different ways. In general, attacks on wireless networks fall into four basic categories: passive attacks, active attacks, man-in-the-middle attacks and jamming attacks.

Passive attacks are by their very nature difficult to detect and are extremely common on wireless networks. A passive attack occurs when someone listens to or eavesdrops on network traffic.

Wireless active attacks include, but are not limited to, unauthorized access, spoofing and Denial of Service (DoS) and flooding attacks, as well as the introduction of malware and the theft of devices. Once the attacker has authenticated and associated with the wireless network, he or she can then run port scans, use special tools to dump user lists and passwords, impersonate users, connect to shares and, in general, wreak havoc on the network through DoS and flooding attacks.

Placing a rogue access point within range of wireless stations is wireless-specific variation of a man-in-the-middle attack. If the attacker knows the SSID in use by the network (which is easily discoverable) and the rogue access point (AP) has enough strength, wireless users will have no way of knowing that they are connecting to an unauthorized AP.

Jamming is a special kind of DoS attack specific to wireless networks. Jamming occurs when spurious RF frequencies interfere with the operation of the wireless network.