Saturday, January 25, 2014

DNSSEC, from an end-user perspective, part 3

In the first post of this DNSSEC series, I have showed the problem (DNS vulnerabilities), and in the second post the "solution". In this third post, I am going to analyze DNSSEC. Can DNSSEC protect the users against all of the attacks? Or just part of them? What about corner cases?

The following list are the attack types from the first post, where DNSSEC can protect the users:

  • DNS cache poisoning the DNS server, "Da Old way"
  • DNS cache poisoning, "Da Kaminsky way"
  • ISP hijack, for advertisement or spying purposes
  • Captive portals
  • Pentester hijacks DNS to test application via active man-in-the-middle
  • Malicious attacker hijacks DNS via active MITM

The following list are the attack types from the first post, where DNSSEC cannot protect the users:

  • Rogue DNS server set via malware
  • Having access to the DNS admin panel and rewriting the IP
  • ISP hijack, for advertisement or spying purposes
  • Captive portals
  • Pentester hijacks DNS to test application via active man-in-the-middle
  • Malicious attacker hijacks DNS via active MITM

If you are a reader who thinks while reading, you might say "What the hell? Am I protected or not???". The problem is that it depends… In case where the attacker is between you and your DNS server, the attacker can impersonate the DNS server, downgrade it to a non DNSSEC aware one, and send responses without DNSSEC information.

Now, how can I protect against all of these attacks? Answer is "simple":
  1. Configure your own DNSSEC aware server on your localhost, and use that as a resolver. This is pretty easy, even I was able to do it using tutorials.
  2. Don't let malware run on your system! ;-)
  3. Use at least two-factor authentication for admin access of your DNS admin panel.
  4. Use a registry lock (details in part 1).
  5. Use a DNSSEC aware OS.
  6. Use DNSSEC protected websites.
  7. There is a need for an API or something, where the client can enforce DNSSEC protected answers. In case the answer is not protected with DNSSEC, the connection can not be established.

Now some random facts, thoughts, solutions around DNSSEC:

That's all folks, happy DNSSEC configuring ;-)

Note from David:
Huhh, I have just accidentally deleted this whole post from Z, but then I got it back from my browsing cache. Big up to Nir Sofer for his ChromeCacheView tool! Saved my ass from kickin'! :D

2 comments :

  1. And I believe you also would like to thank to Google for not storing previous versions ;-)

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    Replies
    1. Ah, it's OK. At least I don't need a f*cking G+ account to use it... :D

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