Wireless LAN Holes

 
 
By Carmen Nobel  |  Posted 2001-02-12 Email Print this article Print
 
 
 
 
 
 
 

WEP protocol hacked, solution nowhere in sight

The integrity of wireless LANs is under attack with the revelation of several holes in the WLAN security protocol. As a result, IT managers and security experts are scrambling to find a solution.

Last week, three researchers—two from the University of California at Berkeley and one from security vendor Zero Knowledge Systems Inc.—announced they had found four flaws in the WEP (Wired Equivalency Privacy) protocol portion of the 802.11 standard and were able to mount successful attacks on it within one day of trying.

The holes, said the researchers, who declined to name the wireless LAN products used for the tests, allow hackers to intercept WLAN traffic sent using WEP. The situation underscores the fact that much of the industrys wireless infrastructure was built without security in mind.

IT personnel now worry that this oversight will continue to manifest itself in more frequent and more sophisticated attacks against wireless networks.

"If you go to true mobile computing over a [WLAN], you really do have to worry about the security of your information," said Mel Cartwright, a project manager who oversaw wireless deployment at VF Corp., an apparel manufacturer in Greensboro, N.C. "Theres a real danger to sending that stuff over a wireless network."

To help allay those fears, VF installed two layers of authentication on its system. But even that may not be enough, experts say.

"Our wireless networks are absolutely more vulnerable than our wired ones are," said David Wagner, a professor of computer science at UC Berkeley and one of the three researchers who identified the flaws in WEP last week. "Maybe 10 or 20 years from now, security will be at the forefront of the process when people design wireless networks, but, for now, youll continue to see these problems."

Nor is WEP the only suspect portion of the wireless world. Wireless Application Protocol has a known security hole that allows eavesdroppers to pluck decrypted packets from transmission points before they are scrambled.

And iMode, the Japanese cellular standard that may soon make its way to the United States thanks to AT&T Corp.s deal with NTT Mobile Communications Network Inc., has been compromised by viruses. This could prove especially troublesome for security administrators, given that iMode devices communicate directly with Web servers via compact HTML.

The problems with WEP wont be resolved for at least a year. A task force within the Institute for Electrical and Electronics Engineers is working on revising WEP with the goal of separating the encryption functions from the authentication functions so that there is more to the security than a group of people sharing a common static Web key.

Task force members said its not clear when the fix will become part of a standard. Meanwhile, vendors continue deploying products based on the nonsecure standard.

"Customers were saying they need security now," said Dave Halasz, manager of software systems for Cisco Systems Inc., in San Jose, Calif. "[But] they couldnt wait for the standard. They need an implementation now."

In the case of the IEEE task force, as with all standards efforts, theres an apparent conflict of interest in that people working on the standard are also working for companies developing proprietary solutions and workarounds. In fact, the person in charge of the security subgroup for future versions of 802.11 works for Cisco and helped to develop the proprietary solution that Cisco now offers.

In the face of the latest questions about wireless security, WLAN manufacturers rushed to say that they offer products that go beyond WEP and, therefore, are less vulnerable than products that depend on WEP alone.

However, a couple of problems lie therein. First, its expensive to add products to a wireless network to make it more secure than WEP does.

"WEP was always considered to be the starting point," said John Drewry, senior director of business development for the wireless connectivity division at 3Com Corp., in Santa Clara, Calif. "Its just a Layer 2 link. One of the things 3Com did was implement a Layer 3 solution on top."

But that means adding plenty of expensive equipment such as virtual private network clients and more server software to the access points and radios that make up a WLAN.

The other problem is that these products have to use proprietary technology, which defeats the purpose of a standard.

But WEP may have been defeated before it left the starting gate. The protocol was never submitted for peer review, which led to elementary mistakes in the cryptography, experts say.

"This is not a good crypto system," said Chris Rouland, director of the X-Force research team at Internet Security Systems Inc., in Atlanta. "It should be inherently untrustworthy because its a proprietary protocol. Its security through obscurity."

 
 
 
 
 
 
 
 
 
 
 

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