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Why One-time Passwords Suck For MITM Attacks

Posted by CmdrTaco on Monday August 18, @05:11PM
from the my-password-is-pass1234 dept.
Security
whitehartstag writes "Black Hat 08 disclosed several SSL VPN and DNS vulnerabilities that caused several people to sit up and take notice. Some of these new exploits performed a brilliant Man-In-The-Middle attack on SSL VPN tunnels. This article walks you through how using certificates, instead of OTP tokens, for second-factor authentication can increase the security of your SSL VPN against these new types of attacks."

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Firehose:Why one-time passwords suck for MITM attacks by whitehartstag (1112871)
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  • The Love Triangle... (Score:5, Funny)

    by kcbanner (929309) * on Monday August 18, @05:17PM (#24650767) Homepage Journal
    Alice and Bob's relationship will be at stake when an unknown interloper...Larry...arrives on the scene. Is this love line segment about to become a love triangle? Will the self-signed certs be accepted?

    Coming to you this fall...Larry is...The Man in the Middle.

  • frequency in the wild ? (Score:5, Interesting)

    by jacquesm (154384) <j @ w w .com> on Monday August 18, @05:21PM (#24650821) Homepage

    I know that there are some people that are very clever at doing these man in the middle attacks, but they usually happen in an academic setting as proof of concept.

    Have there been documented cases of (successful) mitm attacks on banks or other high profile targets ?

  • This is NOT an attack on SSL VPN (Score:5, Interesting)

    by ugen (93902) on Monday August 18, @05:27PM (#24650883)

    This isn't an attack on anything, really.

    Here is what the article says:
    "They will then go to all of the trusted CAâ(TM)s and try to get them to issue them a valid âoeinternal onlyâ certificate with the FQDN of a target sslvpn URL. As soon as they get a success, that company now becomes their target of choice. Remember, the certificate they need can be issued from any trusted CA in the browser and does not need to match the CA that the SSLVPN gateway is using."

    Now, may be I am not understanding the purpose of SSL certificates and the PKI infrastructure in general, but I was under distinct impression that the whole reason those authorities exist is to verify who they give the certificate to, and in such a way that we, users, can trust these certificates.

    If this is not correct, and anyone can with relatively minor effort get certificate for a random domain name from one of recognized cert. authorities - game over, none of this matters, the entire PKI infrastructure is in the crapper.

    So, either we have to deal with cert. authorities signing things they should not or this is not an attack that is worth discussing. Everything else is a half-measure.

  • long story short... (Score:5, Interesting)

    by brunascle (994197) * on Monday August 18, @05:29PM (#24650899)
    The guy was able to buy a certificate for Microsoft's login.live.com, from an undisclosed CA that's trusted by IE by default, because he checked a box saying it was only going to be used for internal use.

    Please reveal the CA. They need to be shut down.

    • Re:long story short... (Score:5, Insightful)

      by jacquesm (154384) <j @ w w .com> on Monday August 18, @05:32PM (#24650943) Homepage

      Shutting them down is stopping short, all the certificates issued by them need to be revoked as well and reissued by another CA after thorough checking.

      If there is one documented case there are likely to be many more undocumented cases.

      • Re:long story short... (Score:5, Insightful)

        by QuoteMstr (55051) <dan.colascione@gmail.com> on Monday August 18, @05:57PM (#24651199)

        Somebody, preferably a government agency, should be in charge of testing CAs. CAs have very strong economic incentives to loosen verification rules in order to compete and sell more certificates. When one CA loosens its rules a little bit, all the others are compelled to do the same to stay competitive. It's a race to the bottom [wikipedia.org].

        Market forces cannot solve the problem because there's a fundamental information asymmetry. Joe Myspace isn't going to understand what a root CA is, much less manually remove it from his browser. And even if he did understand what that meant, would he lose access to his favorite SSL-protected sites for some egghead's paranoid security fears?

        We need regulation, and we need it now. We need several free, worldwide certificate revocation lists [wikipedia.org], and we need agencies running these lists to randomly and anonymous ensure CAs are following the verification rules.

        Having just one CRL gives too much power to one authority, which is especially dangerous if these authorities are organs of government. Browsers should check all CRLs and consider a certificate invalid if, say, two-thirds of the CRLs say to do so.

        In any case, the current situation is untenable.

    • Please reveal the CA. They need to be shut down.

      ... and then the execs need to be drawn and quartered.

      Only partly joking. This is such a flaming case of massive malfeasance that impacts **SO** much more than your run-of-the-mill corruption and other shenanigans. As other posters have noted, this shadiness means certs like this are, in general, complete crap, and given the extent to which many very vital businesses conduct online operations on the basis of these certs, a simple slap on the hand -- or even

      • ...they were then fired for their incompetence.
        ...then they were taken out and beaten to a pulp.
        ...then they were ground up into this powder!

    • Thawte (Score:5, Informative)

      by an.echte.trilingue (1063180) on Monday August 18, @05:51PM (#24651145) Homepage
      Thawte does this; look about halfway down the page [thawte.com]

      I must say that in general I have been unsatisfied with thawte. They gave me a hard time about re-issuing my cert after the debian-ssl debacle and in general their tech support people don't know anything beyond what is already on their site.

      Seriously, I pay over a hundred clams a year just to so that I can have ssl communication without the "OMFG THIS SITE IS GONNA HAXOR YOU" dialog box pop up in user's browsers, and they pull all kinds of monkey business.

      But since verisign owns them, I wouldn't hold my breath for them to be shut down. My guess is the other CAs do this, too.

  • too bad for the new blizzard authenticators (Score:3, Interesting)

    by poetmatt (793785) on Monday August 18, @06:14PM (#24651365) Homepage

    Too bad that the new authenticators from blizzard are OTP's and people are convinced that it is 100% foolproof, as this article tends to prove otherwise.

  • I don't see how this is much better? (Score:4, Interesting)

    by JSBiff (87824) on Monday August 18, @07:21PM (#24652171)

    I might be missing something here, but this article proposes, as a way of trying to make the management of keys/certs easier (which is necessary to implement the client-side certs), to use this "SecureAuth" system. . . which downloads an SSL cert to your computer. So. . . uhh, why can't an attacker intercept this? Well, the answer seems to be (maybe I'm misunderstanding here) that before the SecureAuth system will download the cert to you, it sends you some sort of one-time-password via phone or SMS, which you must enter to get the key . . . but once you've typed in this one time password you got by phone, what prevents the MITM from intercepting that passsword the exact same way it would have been attacking the other one-time-password generated by the keychain fob, and therefor be able to impersonate you to the SecureAuth server and get the client cert which should have been sent to you?

    • Re: (Score:3, Informative)

      by carleton (97218)

      Most VPN Clients I've used support a split tunnel mode... the idea being that data going to your company's internal LAN goes through the VPN tunnel ; data going elsewhere goes outside the tunnel. The idea here is that if you're trying to do stuff on the public network (that's assumed to be less sensitive to begin with), you don't have to wait for the traffic to flow from your computer to your company and then to the site you want (worst case being if you wanted to say stream music off your music server on

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