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1st April 2002 Newsletter of the
Front Range UNIX Users Group

Cndnsd Vrsn: 4 PM Thursday April 4th ACS Room 123- Wireless Insecurity


Wireless Insecurity

The next meeting of the Front Range UNIX Users Group (FRUUG) will be held at 4:00 P.M. on Thursday, April 4th. Dave Clements and Bob Gray of Boulder Labs will talk about how insecure wireless networks can be and how to make yours more secure.

It's alarming that dozens of downtown Boulder companies have wireless networks vulnerable to intruders. And it's even more alarming that these companies might never know if competitors, hackers, or identity thieves have helped themselves to intellectual property, financial information, or other proprietary information.

Wireless technology (also known as 802.11b) is convenient and cheap. A Base-station and a couple of clients cost less than $500. But the resulting network will be terribly insecure unless measures are taken. Boulder Labs recently located 50 networks in the downtown Boulder area alone that were wide open. Bob and Dave drove around with a laptop, an 802.11b card, and an antenna for a few hours. Using open source tools, they identified the locations of the various Base-stations. (See for a map)

Once located, you can monitor and capture network traffic from near or afar. About 60% of the sites transmit plaintext. The remaining sites use WEP Encryption, which can be broken in as little as a few minutes if the common key generating algorithm is used. And if not, there are another half dozen exploits that will eventually defeat both the 64 or 128-Bit WEP Encryption.

This talk will describe what it takes to break the various combinations of WEP Encryption. Bob and Dave will talk about monitoring from afar with simple home-built antennas. Finally, they will discuss various techniques for securing a Wireless network including SSL, ssh, IPsec, and VPN technologies.

Dave Clements and Bob Gray are with Boulder Labs, a Colorado-based software consulting company with expertise in embedded systems, network security, and system administration. Their deployed systems are often based on open-source systems like FreeBSD and Linux. They collaborate with young companies helping them build their products and their network infrastructure.

Meeting Location

This meeting will be in room 123 of the CU Academic Computing Center building at Arapahoe and Marine Streets in Boulder. Marine St intersects Arapahoe at 38th St; the Computing Center is on the southwest corner.

See <> for map

Our Last Meeting

At our March meeting, Cricket Liu discussed security issues with DNS servers and how to prevent yours from being hacked. His slides are avilable in the FRUUG meeting archive at

Future Meetings

We have a great set of meetings lined up for the future. Those with firm dates include:

Other meetings we're planning for the future include UNIX interoperability with MacOS X, IP-based Storage Area Networks (SANs), and an update on how to control spam-- unsolicited e-mail.

FRUUG Giveaways

In February we began our new FRUUG Giveaway program with new eligibility rules. In order to be eligible for our giveaway that includes Gift Certificates to SoftPro Books and Special Giveaway Books from our publisher sponsors (and of course the occasional T-Shirt), you must have earned a FRUUG Library Merit Badge by reviewing one of the books in our library. These reviews can be as short or as long as you like (within reason), and once you've given us one, your eligible for our giveaways from then on. Details are on our FRUUG Library Page on our Web site.

Just so we don't end up with the absurd situation of one person winning all of our giveaways because only one person writes a book review, we're guaranteeing the first ten people to earn the FRUUG Library Merit Badge the gift of your choice from the following selections:

  • A $20 Gift Certificate from SoftPro Books in Boulder or Denver. If more than one person per month selects this option, you'll be put in the queue to get the next one we receive (SoftPro donates one per meeting).

  • The book of your choice from the FRUUG library. Yes, any book you like. Yes, if you're one of the first five, review the book and then keep it.

Six people have already taken advantage of this great offer; the next four reviewers will still be guaranteed the gift certificate or the book of their choice. Please refer to the FRUUG Library Page on our site for details on how to submit a book review.

FRUUG Library Notes

Our FRUUG library sponsors are reminding us that they are providing us with review copies of their books in order to get, well, reviews of them. In order for us to continue to receive their generous donations, we need to start giving them feedback on their books. If you check out a FRUUG book, please plan to write a paragraph on what you thought of the book, or point out areas that you particularly liked or didn't like. They don't have to be polished reviews for publication-- they are reviews for them to improve their books. If you can manage to put a few words together, please send them (along with the title and publisher of the book) to gaede at and we'll send it along to the appropriate people.

New in the library this month are:

  • Building Wireless Community Networks, from O'Reilly & Associates
  • Building Linux Virtual Private Networks (VPNs), from New Riders
  • DNS and BIND, 4th Edition, from O'Reilly & Associates
  • Designing with JavaScript, 2nd Edition, from O'Reilly & Associates
  • Hardening Cisco Routers, from O'Reilly & Associates
  • Proceedings of BSDCon 2002 San Francisco, California, February 2002, from the USENIX Association
  • Proceedings of the Conference on File and Storage Technologies, Monterey, California, January 2002, from the USENIX Association
  • System Performance Tuning, 2nd Edition, from O'Reilly & Associates
  • Using SANs and NAS, from O'Reilly & Associates
  • Web Services Essentials, from O'Reilly & Associates

You may check out books using your business card as your library card; you must be on the membership list to check books out. Books are due at the meeting following the one in which they are checked out.

Remember that your FRUUG membership entitles you to discounts on your book orders from both New Riders Publishing and O'Reilly & Associates; refer to the FRUUG Web site for details.

Site Map Recruiter Info
February 15, 2009

February 2008: FRUUG Enters Quiescent Phase
After 27 years running, we're suspending operations.

Future Meetings:
None planned

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