Cybersecurity

Thoughts About “Protection Against BIND”

Imagine my surprise upon reading a BBC article which identified ISC BIND as the top security vulnerability to UNIX systems. At ISC, we have striven for a decade to repair BIND's reputation, and by all accounts we have made great progress. "What could this be about," I wondered, as I scanned the BBC article for more details. It turns out that BBC was merely parroting what it had been told by SANS. OK, let's see what SANS has to say... more

The State of DNS Abuse: Moving Backward, Not Forward

ICANN's founding promise and mandate are optimistic -- ensure a stable and secure internet that benefits the internet community as a whole. Recent months, however, have highlighted the uncomfortable truth that ICANN's and the industry's approach to DNS abuse is actually moving backward, ignoring growing problems, abdicating on important policy issues, and making excuses for not acting. Further, the impending failure of ICANN's new WHOIS policy to address cybersecurity concerns will add fuel to the fire, resulting in accelerating DNS abuse that harms internet users across the globe. more

Domain Name Association Outlines Healthy Practices as Part of Key Initiative

The domain name system is in good health. But it's about to get even better. The Domain Name Association (DNA), the Internet domain industry's trade association, undertook an effort in 2016 it named the Healthy Domains Initiative (HDI). It's an ambitious, self-motivated effort to build on the DNS' already secure and stable platform and meet select challenges head-on, before they develop. more

Hypertext Mail Protocol (a.k.a. Stub Email): A Proposal

Back in the days of dial-up modems and transfer speeds measured in hundreds of bits per second, unwanted email messages were actually felt as a significant dent in our personal pocketbooks. As increases in transfer speeds outpaced increases in spam traffic, the hundreds of unwanted emails we received per week became more of a nuisance than a serious financial threat. Today sophisticated spam filters offered by all major email providers keep us from seeing hundreds of unwanted emails on a daily basis, and relatively infrequently allow unwanted messages to reach our coveted Inboxes. So, to some degree, the spam problem has been mitigated. But this "mitigation" requires multiple layers of protection and enormous amounts of continually-applied effort. more

IP or NAT IP: Mostly IP

There seems to be a heated debate on this site about NAT (network-address translation). What came as a surprise to me is that a lot of the arguments seem to reside in ideological point of views which obscure the real issues at hand -- IP addressing, IP security -- and have little to do with NAT's actual merits or drawbacks. more

DNS Firewalls In Action - RPZ vs. Spam

In general, a network firewall is just a traffic filter... Filtering rules can be anything from "allow my web server to hear and answer web requests but not other kinds of requests" to "let my users Ping the outside world but do not let outsiders Ping anything on my network." The Internet industry has used firewalls since the mid-1980's and there are now many kinds, from packet layer firewalls to web firewalls to e-mail firewalls. Recently the DNS industry has explored the firewall idea and the results have been quite compelling. In this article I'm going to demonstrate a DNS firewall built using RPZ (Response Policy Zones) and show its potential impact on e-mail "spam". more

Pakistan Hijacks YouTube: A Closer Look

A few hours ago, Pakistan Telecom (AS 17557) began advertising a small part of YouTube's assigned network. This story is almost as old as BGP. Old hands will recognize this as, fundamentally, the same problem as the infamous AS 7007 from 1997, a more recent ConEd mistake of early 2006 and even TTNet's Christmas Eve gift 2005. Just before 18:48 UTC, Pakistan Telecom, in response to government order to block access to YouTube, started advertising a route for 208.65.153.0/24 to its provider... more

A Question of DNS Protocols

One of the most prominent denial of service attacks in recent months was one that occurred in March 2013 between Cloudflare and Spamhaus... How did the attackers generate such massive volumes of attack traffic? The answer lies in the Domain Name System (DNS). The attackers asked about domain names, and the DNS system answered. Something we all do all of the time of the Internet. So how can a conventional activity of translating a domain name into an IP address be turned into a massive attack? 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

Whither DNS?

The Domain Name System is often though of as an integral part of the Internet. Without it, how can you ever locate anything? Well, quite easily, thank you very much. DNS is used implicitly for many services, such as web browsing. It also includes explicit extensions for a few applications such as e-mail. (I'm talking here about DNS the system, not DNS the technology that can be re-purposed to things like ENUM.) But the most notable thing about DNS is its receding importance... more

Fight Spam With the DNS, Not the CIA

It seems like spam is in the news every day lately, and frankly, some of the proposed solutions seem either completely hare-brained or worse than the problem itself. I'd like to reiterate a relatively modest proposal I first made over a year ago: Require legitimate DNS MX records for all outbound email servers.

MX records are one component of a domain's Domain Name System (DNS) information. They identify IP addresses that accept inbound email for a particular domain name. To get mail to, say, linux.com, a mail server picks an MX record from linux.com's DNS information and attempts to deliver the mail to that IP address. If the delivery fails because a server is out of action, the delivering server may work through the domain's MX records until it finds a server that can accept the mail. Without at least one MX record, mail cannot be delivered to a domain.
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Cybersecurity, an Essential Weapon in the Cyberwarfare to Protect Our Democracy

We see the problems that we are facing within an increasingly digital society and economy. We cannot go backward; the only way forward is to ensure that this new digital environment is made as safe as possible from a personal, social, political and economic perspective. We are currently struggling on these fronts. Unfortunately, we have now clearly entered a situation of cyber warfare. States now use digital technologies to impose and undermine ideologies. more

Some Notes on the .XXX Top-Level Domain

Yesterday the ICANN board discussed and approved ICANN staff to enter into negotiations with ICM Registry, Inc. for the .XXX Top Level Domain (TLD). I'm sure there will be a longer more complete presentation from ICANN later about this, but as an individual board member I thought I'd post a quick note before people got carried away with speculation based on a lack of information. more

In Bad Taste

So-called domain tasting is one of the more unpleasant developments in the domain business in the past year. Domain speculators are registering millions of domains without paying for them, in a business model not unlike running a condiment business by visiting every fast food restaurant in town and scooping up all of the ketchup packets. Since 2003, the contract between ICANN and each unsponsored TLD registry (.biz, .com, .info, .net, .org, and .pro) has added an Add Grace Period (AGP) of five days during which a registrant can delete a newly registered domain and get a full refund. Although this provision was clearly intended to allow registrars to correct the occasional typo and spelling error in registrations, speculators realized that this allows them to try out any domain for five days for free... more

A Balkanized Internet Future?

Joi Ito has an important post [also featured on CircleID] on how the internet is in danger of becoming balkanized into separate "internets". He's not the only person who's concerned. Greg Walton worries about Regime Change on the Internet. My friend Tim Wu, a law professor specializing in international trade and intellectual property, has written an article for Slate: The Filtered Future: China's bid to divide the Internet... more