Kevin- I agree with this classic arguement. But- how many times do we tend to hit "there is a problem with this certificate, are you sure you want to proceed?" type errors, and accept whatever the problem is and move on? My take is that the a valid cert helps, but only if users have a clue to recognize signs of trouble and respond responsibly. So even with a good cert, some users will "fall for" a craftily crafted MITM attack because they just don't get it. These are the same people who click every pop up that promises something good, then hose the machine...
Lee Lee Badman, KC2IYK Network/Wireless Engineer CWNA, CWSP Information Technology and Services Syracuse University 315 443-3003 >>> [EMAIL PROTECTED] 4/5/2007 11:12 AM >>> Understand, though, that if someone puts up an access point with your SSID, the clients will connect and because they aren't validating the certificate, they will send their credentials to the "rogue" AP. -Kevin ktaillon wrote: > One of the things that I didn't point out is we are running the new LWAPP > AP's and controller setup. After I told Cisco about the one-way cert he said > this is ok to run in this setup because the peap tunnel that is created from > the client to the AP and to the ACS/Controller could not be interfered with. > Not like a web server cert that could be hijacked. > > If I were to install a Cert(Verisign, GTE.....)on the ACS that is on the XP > list of trusted names, can the client just check off that name without > having to go to a web server to download and install the cert? > > I'm just trying to keep the client setup as simple as possible but not in a > way that lowers security. > > Ken > > > -----Original Message----- > From: Michael Griego [mailto:[EMAIL PROTECTED] > Sent: Wednesday, April 04, 2007 11:27 AM > To: [email protected] > Subject: Re: [WIRELESS-LAN] 802.1x With A One-Way Certificate > > Just be aware that not validating the certificate opens you up to fairly > easy session hijacking attacks since anyone can come up with a cert and get > your clients to connect to their APs instead of yours (since the client is > not checking cert validity)... The attacker would then have access to the > data stream as it would appear on the LAN, so you potentially lose a lot of > the security benefit. > > --Mike > > > On Apr 4, 2007, at 10:19 AM, Rick Coloccia wrote: > >> Yes. We aren't using the wpa-tkip with acs, but we do use ias >> (windows) for radius, we have our clients uncheck the 'Validate Server >> Certificate' option and away they go. >> >> http://www.geneseo.edu/CMS/display.php?page=5200&dpt=cit >> http://www.geneseo.edu/CMS/display.php?page=5198&dpt=cit >> http://www.geneseo.edu/CMS/display.php?page=5199&dpt=cit >> >> We like how it works. We run 4 4404's with 350 1242ag access points. >> >> -Rick >> >> >> ktaillon wrote: >>> We are trying to implement a WPA/TKIP Wireless authentication. We are >>> using ACS Solution Engine which backs into AD for Authentication. We >>> are currectly using WEP. >>> We are looking for the least amount of client setup to make this >>> change. Cisco has told us to use the PEAP MSCHAPv2 connection with a >>> one-way cert, the cert or CA would only be installed on the ACS >>> server and the client would uncheck the 'Validate Server Certificate' >>> under the protected EAP properties. They also told us that the PEAP >>> tunnel that is created would be comparable to having a cert on the >>> client. This seems to be working fine in our tests and is very simple >>> setup for the clients. >>> Are any of you running your connection setup this way? >>> Ken Taillon >>> Network Support Specialist >>> Information Technology Services >>> Wesleyan University >>> 860-685-5657 >>> ********** Participation and subscription information for this >>> EDUCAUSE Constituent Group discussion list can be found at http:// >>> www.educause.edu/groups/. >> -- >> Rick Coloccia, Jr. >> Network Manager >> State University of NY College at Geneseo >> 1 College Circle, 119 South Hall >> Geneseo, NY 14454 >> V: 585-245-5577 >> F: 585-245-5579 >> >> ********** >> Participation and subscription information for this EDUCAUSE >> Constituent Group discussion list can be found at http:// >> www.educause.edu/groups/. > > > ********** > Participation and subscription information for this EDUCAUSE Constituent > Group discussion list can be found at http://www.educause.edu/groups/. > > ********** > Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/. ********** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/. ********** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/.
