Posted by: Ken Harthun
DNS Rebinding Attack, Security, Security Now!, Vulnerabilities
Consider me duly humbled. I took Steve Gibson to task for reporting on the DNS Rebinding attack that has been in the news. I thoroughly misunderstood Steve’s take on it. Here is exactly what he said in the Security Now! episode 258:
I want to discuss this in detail in two weeks because it’s an interesting type of attack that we haven’t discussed in the past. It’s been around and has been known for a while. And it’s sneaky. And it will make for a great detailed coverage in two weeks. It’s called a DNS Rebinding Attack. And it’s in the news now because someone named Craig Heffner is going to be presenting at the Black Hat conference at the end of this month his presentation titled “How to Hack Millions of Routers.”
Pretty clear, don’t you think? Well, it is–now that I look back on it–but you know how emotion can get in the way sometimes. Here’s our email exchange:
Me: Hi Steve, I’ve been a loyal Security Now! listener since Episode 1 and I value your insight on current security issues. Haven’t missed a single episode (If I did, I’d have withdrawal symptoms!) However, I have to take issue with your reporting in Episode #258, that there is something new about what is really an old, stale issue: DNS Rebinding Attacks. It seems that when someone wants some attention (not referring to you, of course) they take a new twist on this one. In other words–different guy, same vulnerability.
Steve: Hi Ken! Thanks very much for your note. I certainly agree with you that DNS Rebinding has been around for awhile, and I did also mention that last week. Mostly the reason I’m bringing it up is that active attacks using it are around again … but more than that … because it’s something that we’ve never covered in detail on the Security Now podcast and I think it’s a clever and conceptionally interesting vulnerability/hole/glitch. It also perfectly demonstrates, I think, the inherent trouble with the ever-growing complexity of our systems.
Me: Hi Steve, So good to hear from you. Thanks for the clarification. DNS Rebinding certainly is a clever trick and am definitely going to be looking forward to your analysis of it. You’re not kidding about complexity in our systems being the inherent trouble. As you say “complexity is the enemy of security.” That’s one of my mantras.
Steve: Hi again Ken… I’ve also just realized that I can add DNS Rebinding Attack protection detection to my (still) forthcoming DNS Benchmark. I’m already detecting and alerting users to domain name error (NXDOMAIN) redirections. So checking for rebinding protection would be very cool too! Thanks again for your note!
For the record, I goofed. I should have thought it out a bit before I hit the Send button, but it resulted in a very pleasant exchange with a guy I respect, so I guess it’s all good.