DNS Security


 DNSSEC technology standards have been stable and mature since 2007, with only updates, clarifications, and new functionality added since then.

 Over the next few years we should expect to see applications leveraging DNSSEC in ways we cannot imagine now.

 The movement is on, DNSSEC, ready set go! Just make sure you are ready when you go!

 Some folks have already asked me if DNSSEC could have prevented Twitter.com traffic from being hijacked. In this case, the answer is, "No".

DNS Security / Most Viewed

Internationalizing the Internet

One topic does not appear to have a compellingly obvious localization solution in the multi-lingual world, and that is the Domain Name System (DNS). The subtle difference here is that the DNS is the glue that binds all users' language symbols together, and performing localized adaptations to suit local language use needs is not enough. What we need is a means to allow all of these language symbols to be used within the same system, or "internationalization". more»

Cricket Liu Interviewed: DNS and BIND, 5th Edition

In follow-up to recent announcement on the release of the latest edition of the very popular DNS and BIND book -- often referred to as the bible of DNS -- CircleID has caught up with Cricket Liu, co-author and a world renowned authority on the Domain Name System. In this interview, Cricket Liu talks about emerging issues around DNS such as security and IPv6 support, and important new features such as internationalized domain names, ENUM (electronic numbering), and SPF (the Sender Policy Framework). "Cricket Liu: We're now seeing more frequent attacks against DNS infrastructure. ...Turns out that name servers are terrific amplifiers -- you can get an amplification factor of nearly 100x. These attacks have raised awareness of the vulnerability of Internet name servers, which is possibly the only positive result..." more»

Experts Urge Congress to Reject DNS Filtering from PROTECT IP Act, Serious Technical Concerns Raised

A group of leading DNS experts have released a paper detailing serious concerns over the proposed DNS filtering requirements included as part of the bill recently introduced in the U.S. Senate named Preventing Real Online Threats to Economic Creativity and Theft of Intellectual Property Act of 2011 ("PROTECT IP Act"). The group who is urging lawmakers to reconsider enacting such a mandate into law, includes leading DNS designers, operators, and researchers, responsible for numerous RFCs for DNS, publication of many peer-reviewed academic studies related to architecture and security of the DNS, and responsible for the operation of important DNS infrastructure on the Internet. more»

A Fundamental Look at DNSSEC, Deployment, and DNS Security Extensions

In looking at the general topic of trust and the Internet, one of the more critical parts of the Internet's infrastructure that appears to be a central anchor point of trust is that of the Domain Name Service, or DNS. The mapping of "named" service points to the protocol-level address is a function that every Internet user relies upon, one way or another. The ability to corrupt the operation of the DNS is one of the more effective ways of corrupting the integrity of Internet-based applications and services. If an attacker can in some fashion alter the DNS response then a large set of attack vectors are exposed. ...The more useful question is whether it is possible to strengthen the DNS. The DNS is a query -- response application, and the critical question in terms of strengthening its function is whether it is possible to authenticate the answers provided by the DNS. DNSSEC provides an answer to this question. more»

DNSSEC: Once More, With Feeling!

After looking at the state of DNSSEC in some detail a little over a year ago in 2006, I've been intending to come back to DNSSEC to see if anything has changed, for better or worse, in the intervening period... To recap, DNSSEC is an approach to adding some "security" into the DNS. The underlying motivation here is that the DNS represents a rather obvious gaping hole in the overall security picture of the Internet, although it is by no means the only rather significant vulnerability in the entire system. One of the more effective methods of a convert attack in this space is to attack at the level of the DNS by inserting fake responses in place of the actual DNS response. more»

Defending Networks Against DNS Rebinding Attacks

DNS rebinding attacks are real and can be carried out in the real world. They can penetrate through browsers, Java, Flash, Adobe and can have serious implications for Web 2.0-type applications that pack more code and action onto the client. Such an attack can convert browsers into open network proxies and get around firewalls to access internal documents and services. It requires less than $100 to temporarily hijack 100,000 IP addresses for sending spam and defrauding pay-per-click advertisers. Everyone is at risk and relying on network firewalls is simply not enough. In a paper released by Stanford Security Lab, "Protecting Browsers from DNS Rebinding Attacks," authors Collin Jackson, Adam Barth, Andrew Bortz, Weidong Shao, and Dan Boneh provide ample detail about the nature of this attack as well as strong defenses that can be put in place in order to help protect modern browsers. more»

About Those Root Servers

There is an interesting note on the ITU Strategy and Policy Unit Newslog about Root Servers, Anycast, DNSSEC, WGIG and WSIS about a presentation to ICANN's GAC. (The GAC website appears to be offline or inaccessible today.) The interesting sentence is this: Lack of formal relationship with root server operators is a public policy issue relevant to Internet governance. It is stated that this is "wrong" and "not a way to solve the issues about who edits the [root] zone file." Let's look at that lack of a formal relationship... more»

Microsoft's Takedown of 3322.org - A Gigantic Self Goal?

I will first begin this post by emphasizing that this article is entirely my personal viewpoint and not to be considered as endorsed by or a viewpoint of my employer or any other organization that I am affiliated with. Neither is this to be considered an indictment of the sterling work (which I personally value very highly) that several people in Microsoft are doing against cybercrime. Microsoft's takedown of 3322.org to disrupt the Nitol botnet is partial and will, at best, have a temporary effect on the botnet itself... more»

DNS, DNSSEC and Google's Public DNS Service

For some time now we've been tracking the progress of the deployment of DNSSEC in the Internet. Its been a story of an evolution of the measurement technique... In the process we've learned perhaps more than we had wanted to about the behaviour of Flash engines, Apache web servers and FreeBSD system tuning, and also learned much more than we had anticipated about the finer details of Google's online ad presentation behaviour. But one thing we did not see in all of this was any large scale jumps in the level of client use of DNSSEC validation over this period at the start of the year. more»

Social Networking and Web 2.0 Creating DNS Performance Issues for Carriers

A revolution is taking place on the Internet, with new sites redefining how we interact online. The next-generation Internet is emerging in collaborative and interactive applications and sites with rich, varied media (images, video, music). As with many revolutions, this one is driven by the younger generation, which is adopting social networking sites like MySpace and video sharing sites like Google's YouTube. But the general shift is not restricted to the young, as more mature consumers and businesses alike are exploring the possibilities of collaborative, media-rich applications. This major shift in Internet applications has its unintended victims. One of them turns out to be the Domain Name System (DNS). more»

Technical Comments on Mandated DNS Filtering Requirements of H. R. 3261 ("SOPA")

About two months ago, I got together with some fellow DNS engineers and sent a letter to the U. S. Senate explaining once again why the mandated DNS filtering requirements of S. 968 ("PIPA") were technically unworkable. This letter was an updated reminder of the issues we had previously covered... In the time since then, the U. S. House of Representatives has issued their companion bill, H. R. 3261 ("SOPA") and all indications are that they will begin "markup" on this bill some time next week. more»

The Problem With HTTPS SSL Runs Deeper Than MD5

The recent research highlighting the alarming practice of Secure Socket Layer (SSL) Certificate Authority (CA) vendors using the MD5 hashing algorithm (which was known to be broken since 2005) has shown a major crack in the foundation of the Web. While the latest research has shown that fake SSL certificates with MD5 hashes can be forged to perfection when the CA (such as VeriSign's RapidSSL) uses predictable certificate fields, the bigger problem is that the web has fundamentally botched secure authentication. more»

The Case Against DNSSEC

I was talking to my good friend Verner Entwhistle the other day when he suddenly turned to me and said "I don't think we need DNSSEC". Sharp intake of breath. Transpired after a long and involved discussion his case boiled down to four points: 1. SSL provides known and trusted security, DNSSEC is superfluous, 2. DNSSEC is complex and potentially prone to errors, 3. DNSSEC makes DoS attacks worse, 4. DNSSEC does not solve the last mile problem. Let's take them one at a time... more»

Refusing REFUSED

The U.S. Congress' road to Stopping Online Piracy (SOPA) and PROTECT IP (PIPA) has had some twists and turns due to technical constraints imposed by the basic design of the Internet's Domain Name System (DNS). PIPA's (and SOPA's) provisions regarding advertising and payment networks appear to be well grounded in the law enforcement tradition called following the money, but other provisions having to do with regulating American Internet Service Providers (ISPs) so as to block DNS resolution for pirate or infringing web sites have been shown to be ineffectual, impractical, and sometimes unintelligible. more»

The Cybersecurity Act of 2009

Four senators (Rockefeller, Bayh, Nelson, and Snowe) have recently introduced S.773, the Cybersecurity Act of 2009. While there are some good parts to the bill, many of the substantive provisions are poorly thought out at best. The bill attempts to solve non-problems, and to assume that research results can be commanded into being by virtue of an act of Congress. Beyond that, there are parts of the bill whose purpose is mysterious, or whose content bears no relation to its title. more»