A Good Security Policy Goes a Long Way to Protect Against Wi-Fi DoS

By Carol Ellison  |  Posted 2004-05-14 Print this article Print

Security watchdogs in Australia revealed another Wi-Fi vulnerability this week. One more reason to adopt—and enforce—a security policy.

Question: When is a Wi-Fi vulnerability not a vulnerability? Answer: When the vulnerability plays into defenses against attacks. That may be the case with an advisory issued this week by AusCERT, Australias national computer emergency response team.
The advisory described how a protocol characteristic of wireless networks can be exploited to stage a denial-of-service (DoS) attack.
For a moment when the news hit on Thursday, it looked like déjà vu all over again. It seems like only yesterday that, with great relief, we said "goodbye" to the vulnerabilities of Wired Equivalent Privacy security in the original 802.11 spec and "hello" to the strong encryption and enterprise authentication in Wi-Fi Protected Access (WPA), the mechanism that replaced it. Finally, we had the wired equivalent security that WEP promised but never delivered. Now, here comes the AusCERT advisory and something new for WLAN administrators to worry about? Its cause for caution. But if youre already enforcing good security policies, dont lose too much sleep just yet. On the scale of attacks that merit insomnia, this one is on the low side. There are two major classes of network attacks—passive and active. A DoS attacker must be actively involved in the attack so it naturally falls into the active category. On the Internet the attackers presence is hard to detect due to the international and anonymous nature of the Net. But in the Wi-Fi world, where a radio signal is involved, its relatively easy if you have the right equipment. The nature of the beast, when it goes wireless, is that its trackable and its effect is limited—confined to 802.11b devices within its range. An attack of short enough duration to avoid detection is not likely to cause serious disruption. That means less disruption, fewer kicks and a potential jail sentence for the attacker. Enforcing strong security policies across the WLAN will minimize this and other vulnerabilities. That should go without saying, shouldnt it? But as news reports testify, every time a reporter goes on a war-driving expedition to identify WLAN vulnerabilities, there are network managers that havent got religion. There are still companies that havent deployed WLAN intrusion detection, havent graduated to WPA and havent even enabled WEP. Oh when will they ever learn… Check out eWEEKs Mobile & Wireless Center at http://wireless.eweek.com for the latest news, reviews and analysis.
Carol Ellison is editor of eWEEK.com's Mobile & Wireless Topic Center. She has authored whitepapers on wireless computing (two on network security–,Securing Wi-Fi Wireless Networks with Today's Technologies, Wi-Fi Protected Access: Strong, Standards-based Interoperable Security for Today's Wi-Fi Networks, and Wi-Fi Public Access: Enabling the future with public wireless networks.

Ms. Ellison served in senior and executive editorial positions for Ziff Davis Media and CMP Media. As an executive editor at Ziff Davis Media, she launched the networking track of The IT Insider Series, a newsletter/conference/Web site offering targeted to chief information officers and corporate directors of information technology. As senior editor at CMP Media's VARBusiness, she launched the Web site, VARBusiness University, an online professional resource center for value-added resellers of information technology.

Ms. Ellison has chaired numerous industry panels and has been quoted as a networking and educational technology expert in The New York Times, Newsday, The Los Angeles Times and The Wall Street Journal, National Public Radio's All Things Considered, CNN Headline News, WNBC and CNN/FN, as well as local and regional Comcast and Cablevision reports. Her articles have appeared in most major hi-tech publications and numerous newspapers and magazines, including The Washington Post and The Christian Science Monitor.

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