Security

Live free or die: Death is not the worst of evils.
- General John Stark

Is life so dear, or peace so sweet, as to be purchased at the price of chains and slavery? Forbid it, Almighty God! I know not what course others may take; but as for me, give me liberty or give me death!
- Patrick Henry

Privacy, n.
1. The state or condition of being alone, undisturbed, or free from public attention, as a matter of choice or right; seclusion; freedom from interference or intrusion.
2. The state of being privy to some act
3. a. Absence or avoidance of publicity or display; secrecy, concealment, discretion; protection from public knowledge or availability.
3. b. The keeping of a secret; reticence.
- Oxford English Dictionary

Privacy is often taken for granted. When the US Constitution was drafted, the founding fathers made sure to put in provisions to guarantee the privacy of the citizens they would govern. Most scholars agree that their intention was to prevent government intrusion in private lives and activities. They were very forward thinking, trying to ensure this protection would continue indefinitely into the future. Unfortunately, even the most forward thinking, well intentioned individual won't be able to cover all of the possible scenarios that will occur in the future.

Since that fateful day in 1787, a war has raged between those advocating absolute privacy and those advocating reasonable intrusion for the sake of security. At the extreme edge of the argument are the non-consequentialists who believe that privacy should be absolute. They believe that privacy is non-negotiable and that the loss of privacy is akin to slavery. A common argument is that giving up privacy merely encourages additional loss. In other words, if you allow your privacy to be compromised once, then those that violate it will expect to be able to violate it again.

At the other edge are those that believe that privacy is irrelevant in the face of potential evil. This is also a non-consequentialist view. Individuals with this view tend to argue that if you have something to hide, then you are obviously guilty of something.

Somewhere in the middle are the consequentialists who believe that privacy is essential to a point. Violation of privacy should be allowed when the benefit of doing so outweighs the benefit of keeping something private. In other words, if disclosing a secret may save a life, or prevent an innocent person from going to jail, then a violation of privacy should be allowed.

The right to privacy has been fought over for years. In more recent years, technological advances have brought to light many of the problems with absolute privacy, and at the same time, have highlighted the need for some transparency. Technology has benefits for both the innocent and the criminal. It makes no delineation between the two, offering the same access to information for both.

New technologies have allowed communication over long distances, allowing criminals to coordinate criminal activities without the need to gather. Technology has brought devastating weaponry to the average citizen. Terrorists can use an Internet search engine to learn how to build bombs, plan attacks, and communicate with relative privacy. Common tools can be used to replicate identification papers, allowing criminals access to secure areas. The Internet can be used to obtain access to remote systems without permission.

Technology can also be used in positive ways. Mapping data can be used to optimize travel, find new places, and get you home when you're lost. Online stores can be used to conveniently shop from your home, or find products you normally wouldn't have access to. Social networking can be used to keep in touch with friends and relatives, and to form new friendships with strangers you may never have come in contact with otherwise. Wikipedia can be used for research and updated by complete strangers to spread knowledge. Companies can stay in contact with customers, alerting them of new products, updates to existing ones, or even alert them to potential problems with something they previously purchased.

In the last ten or so years, privacy in the US has been "under attack." These so-called attacks come from many different sources. Governmental agencies seek access to more and more private information in order to combat terrorism and other criminal activities. Private organizations seek to obtain private information to identify new customers, customize advertisements, prevent fraud, etc. Technology has enabled these organizations to obtain this data in a variety of ways, often unbeknownst to the average user.

When was the last time you went to the airport and waited for someone to arrive at the gate? How about escorting someone to the gate before their flight? As recently as 20 years ago, it was possible to do both. However, since that time, security measures have been put in place to prevent non-ticketed individuals access beyond security checkpoints. Since the 9/11 terrorist attacks, security has been enhanced to include random searches, bomb sniffing, pat downs, full-body scanners, and more. In fact, the Transportation Security Administration (TSA) started random screening at the gate in 2008. Even more recently, the TSA has authorized random swabbing of passenger hands to detect explosive residue. While these measures arguably enhance security, it does so at the expense of the private individual. Many travelers feel violated by the process, even arguing that they are assumed to be guilty, having to prove their innocence every time they fly.

Traditionally, any criminal proceeding is conducted with the assumption of innocence. A criminal is considered innocent of a crime unless and until they are proven guilty. In the airport example above, the passengers are being screened with what can be considered an assumption of guilt. If you refuse to be screened, you are barred from flying, if lucky, or taken in for additional questioning and potentially jailed for the offense. Of course, individuals are not granted the right to fly, but rather offered the opportunity at the expense of giving up some privacy. It's when these restrictions are applied to daily life, without the consent of the individual, that more serious problems arise.

Each and every day, the government gathers information about its citizens. This information is generally available to the public, although access is not necessarily easy. How this information is used, however, is often a source of criticism by privacy advocates. Massive databases of information have been built with algorithms digging through the data looking for patterns. If these patterns match, the individuals to whom the data belongs can be subject to additional scrutiny. This "fishing" for wrongdoing is often at the crux of the privacy argument. Generally speaking, if you look hard enough, and you gather enough data, you can find wrongdoing. More often, however, false positives pop up and individuals are subjected to additional scrutiny without warrant. In some cases, individuals can be wrongly detained.

Many privacy opposers argue that an innocent person has nothing to hide. However, this argument can be considered a fallacy. Professor Daniel Solove wrote an essay explaining why this argument is faulty. He argues that the "nothing to hide argument" is essentially hollow. Privacy is an inherently individualistic preference. Without knowing the full extent of how information will be used, it is impossible to say that revealing everything will have no ill effects, assuming the individual is innocent of wrongdoing. For instance, data collected by the government may not be used to identify you as a criminal, but it may result in embarrassment or feelings of exposure. What one person may consider a non-issue, others may see as evil or wrong.

These arguments extend beyond government surveillance and into the private sector as well. Companies collect information about consumers at an alarming rate. Information entered into surveys, statistics collected from websites, travel information collected from toll booths, and more can be used to profile individuals. This information is made available, usually at a cost, to other companies or even individuals. This information isn't always kept secure, either. Criminals often access remote systems, obtaining credit card and social security numbers. Stalkers and pedophiles use social networking sites to follow their victims. Personal information posted on public sites can find its way into credit reports and is even used by some businesses to justify firing employees.

Privacy laws have been put in place to prevent such abuses, but information is already out there. Have you taken the time to put your name into a search engine lately? Give it a try, you may be surprised by the information you can find out about yourself. These are public records that can be accessed by anyone. Financial and real estate information is commonly available to the public, accessible to those knowing how to look for it. Criminal records and court proceedings are published on the web now, allowing anyone a chance to access it.

Whenever you access a website, check out a book from the library, or chat with a friend in email, you run the risk of making that information available to people you don't want to have it. In recent years, it has been common for potential employers to use the Internet to obtain background information on a potential employee. In some cases, embarrassing information can be uncovered, casting a negative light on an individual. Teachers have been fired because of pictures they posted, innocently, on their profile pages. Are you aware of how the information you publish on the Internet can be used against you?

There is no clear answer on what should and should not be kept private. Likewise, there is no clear answer on what private data the government and private companies should have access to. It is up to you, as an individual, to make a conscious choice as to what you make public. In an ever evolving world, the decisions you make today can and will have an impact on what may happen in the future. What you may think of as an innocent act today can potentially be used against you in the future. It's up to you to fight for your privacy, both from the government, and from the companies you interact with. Be sure you're aware of how your data can be used before you provide it. Privacy and private data is being used in new, interesting, and potentially harmful ways every day. Be sure you're aware of how your data can be used before you provide it.

Nanog 46 is wrapping up today and it has been an incredible experience. This particular Nanog seemed to have an underlying IPv6 current to it, but, if you believe the reports, IPv6 is going to have to become the standard in the next couple of years. We'll be running dual-stack configurations for some time to come, but IPv6 rollout is necessary.

To date, I haven't had a lot to do with IPv6. A few years ago I set up one of the many IPv6 shims, just to check out connectivity, but never really went anywhere with it. It was nothing more than a tech demo at the time, with no real content out there to bother with. Content exists today, however, and will continue to grow as time moves on.

IPv6 connectivity is still spotty and problematic for some, though, and there doesn't seem to be a definitive, workable solution. For instance, if your IPv6 connectivity is not properly configured, you may lose access to some sites as you receive DNS responses pointing you at IPv6 content, but that you cannot reach. This results in either a major delay in falling back to IPv4 connectivity, or complete breakage. So one of the primary problems right now is whether or not to send AAAA record responses to DNS requests when the IPv6 connectivity status of the receiver is unknown. Google, from what I understand, is using a whitelist system. When a provider has sufficient IPv6 connectivity, Google adds them to their whitelist and the provider is then able to receive AAAA records.

Those problems aside, I think rolling out IPv6 will be pretty straightforward. My general take on this is to run dual-stack to start, and probably for the forseeable future, and getting the network to hand out IPv6 addresses. Once that's in place, then we can start offering AAAA records for services. I'm still unsure at this point how to handle DNS responses to users with possibly poor v6 connectivity.

Another area of great interest this time around is DNSSEC. I'm still quite skeptical about DNSSEC as a technology, partly due to ignorance, partly due to seeing problems with what I do understand. Rest assured, once I have a better handle on this, I'll finish up my How DNS Works series.

I'm all for securing the DNS infrastructure and doing something to ensure that DNS cannot be poisoned the same way it can today. DNSSEC aims to add security to DNS such that you can trust the responses you receive. However, I have major concerns with what I've seen of DNSSEC so far. One of the bigger problems I see is that each and every domain (zone) needs to be signed. Sure, this makes sense, but my concern is the cost involved to do so. SSL Certificates are not cheap and are a recurring cost. Smaller providers may run into major issues with funding such security. As a result, they will be unable to sign their domains and participate in the secure infrastructure.

Another issue I find extremely problematic is the fallback to TCP. Cryptographic signatures are big, and they tend to be bigger, the larger the key you use. As a result, DNS responses are exceeding the size of UDP and falling back to TCP. One reason DNS works so well today is that the DNS server doesn't have to worry about retransmissions, state of connections, etc. There is no handshake required, and the UDP packets just fly. It's up to the client to retransmit if necessary. When you move to TCP, the nature of the protocol means that both the client and server need to keep state information and perform any necessary retransmissions. This takes up socket space on the server, takes time, and uses up many more CPU cycles. Based on a lightning talk during today's session, when the .ORG domain was signed, they saw a 100-fold increase in TCP connections, moving from less than 1 query per second to almost 100. This concerns me greatly as the majority of the Internet has not enabled DNSSEC at this point. I can see this climbing even more, eventually overwhelming the system and bringing DNS to its knees.

I also believe that moving in this direction will allow the "bad guys" to DoS attack servers in much easier ways as they can easily trigger TCP transactions, perform various TCP-based attacks, and generally muck up the system further.

So what's the alternative? Well, there is DNSCurve, though I know even less about that as it's very much a fringe technology at this point. In fact, the first workable patch against djbdns was only released in the past few weeks. It's going to take some time to absorb what's out there, but based on the current move to DNSSEC, my general feeling is that no matter how much better DNSCurve may or may not be, it doesn't have much of a chance. Even so, there's a lot more to learn in this arena.

I also participated in a Security BOF. BOFs are, essentially, less structured talks on a given subject. There is a bit more audience participation and the audience tends to be a bit smaller. The Security BOF was excellent as there were conversations about abuse, spam, and methods of dealing with each. The spam problem is, of course, widespread and it's comforting to know that you're not the only one without a definitive answer. Of course, the flip side of that is that it's somewhat discouraging to know that even the big guys such as Google are still facing major problems with spam. The conversation as a whole, though, was quite enlightening and I learned a lot.

One of the more exciting parts of Nanog for me, though, was to meet some of the Internet greats. I've talked to some of these folks via email and on various mailing lists, but to meet them in person is a rare honor. I was able to meet and speak with both Randy Bush and Paul Vixie, both giants in their fields. I was able to rub elbows with folks from Google, Yahoo, and more. I've exchanged PGP keys with several people throughout the conference, serving as a geek's autograph. I have met some incredible people and I look forward to talking with them in the future.

If you're a network operator, or your interests lie in that direction, I strongly encourage you to make a trip to at least one NANOG in your lifetime. I'm hooked at this point and I'm looking forward to being able to attend more meetings in the future.

I'm here in sunny Philadelphia, attending NANOG46, a conference for network operators. The conference, thus far, has been excellent, with some great information being disseminated. One of the talks was by a long-time Internet pioneer, Paul Vixie. Vixie has had his hands in a lot of different projects ranging from being the primary author of BIND for many years, starting MAPS way back in 1996, and more recently, involvement with the Conficker Working Group.

Vixie's talk was titled "Internet Superbugs and The Art of War," and was about the struggle between Internet operators and the "criminal" element that uses the Internet for spam, DDOS attack, etc. The crux of the talk centered around the fact that it costs the bad guys next to nothing to continually evolve their attacks and use the network for their nefarious activities. On the flip side, however, it costs the network operators a good deal of time and money to try and stop these attacks.

Years ago, attacks were generally sourced from a single location and it was relatively easy to mitigate them. In addition, tracking down the source of the attack was simple enough, so legal action could be taken. At the very least, the network provider upstream from the attacker could disable the account and stop the attack.

Fast forward to today and we have botnets that are used for sending spam, performing DDOS attacks, and causing other sorts of havoc. It becomes next to impossible to mitigate a DDOS attack because the attack can be sourced from hundreds and thousands of machines simultaneously. This costs the bad guys nothing to deploy because users are largely ignorant and don't understand the importance of patching and securing their networks. This results in millions of machines on the Internet that are exploitable. The bad guys write viruses, worms, trojans, etc. that infect these machines and turn them into zombie machines for their botnet.

Fighting these attacks becomes an exercise in futility. We use blacklists to block traffic from places we know are sending spam, we use anti-virus software to prevent infection of our machines, and more. When Conficker was detected and analyzed, researchers realized that this infection was a new evolution of attack. Conficker used cryptographic signatures to verify updates, pseudo-random lists of websites for updates, and more. The website lists are an excellent example of the costs paid by the good guys vs the bad guys.

The first generation of Conficker used a generated list of websites for updates. This list was 250 sites per day, making it difficult, but not impossible to mitigate. So, the people fighting this outbreak started buying up these domains in an attempt to prevent Conficker from updating. The authors of Conficker responded by upping this list to 50,000 per day, making it nearly impossible to buy them up. Fortunately, the people working to prevent the outbreak were able to work with ICANN and the various ccTLD companies to monitor and block purchases of these sites. Sites that already existed were thoroughly checked to ensure they weren't hosting the new version of Conficker.

Vixie brought up an interesting point about all of this activity, though. The authors of Conficker made a relatively simple change to Conficker to make it use 50,000 domains. The people fighting Conficker spent many hours and days, not to mention a significant amount of money, to mitigate this. Smaller ccTLD companies that don't have 24x7 abuse staff are unable to cope. They don't have the budget to be able to do all of this work for free. As the workload climbs, they're more likely to turn a blind eye.

All of this, in turn, means that our current mode of reacting to these attacks and mitigating them does not scale. It merely results in lost revenue and frustration. Additionally, creating lists of places to avoid, generating lists of bad content, etc. will never be able to scale over time. There is a breaking point, somewhere, and at that point we have no recourse unless we change our way of thinking.

Along the same line of thought, I came across a pretty decent quote today, originally posted by Don Franke from ISC(2):

"PC security is no longer about a virus that trashes your hard drive. It's about botnets made up of millions of unpatched computers that attack banks, infrastructures, governments. Bandwidth caps will contribute to this unless the thinking of Internet providers and OS vendors change. Because we are all inter-connected now."

If you read the original post, it explains how moving to bandwidth caps will only exacerbate the security problem because users will no longer be interested in wasting time downloading updates, but rather saving that bandwidth for things they're interested in.

Overall, it was a very interesting talk and a very different way of thinking. There is no definitive answer as to what direction we need to go in to resolve this, but it's definitely something that needs to be investigated.

April 1, 2009. The major media outlets are all over this one. Digital Armageddon. The end of computing as we know it. Again. But is it? Should we all just "Chill Out?"

So what happens April 1, 2009? Well, Conficker activates. Well, sort of. It activates the latest revision of its auto-update algorithm, switching the number of domains it can find updates on from 250 per day to 50,000 per day. Conficker, in its current form, isn't really malicious beyond techniques to prevent detection. In order to become malicious, it will need to download an update to the base code.

There are two methods by which Conficker will update its base code. The first method is to download the code via a connection to one of the 50,000 domains it generates. However, it does not scan all 50,000 domains at once. Instead, it creates a random list of 500 of the 50,000 generated domains and scans them for an update. If no update is found, Conficker sleeps for 24 hours and starts over by generating a new list of 50,000 domains, randomly picking 500, and contacting them for an update. The overall result of this is that it becomes nearly impossible to block all of the generated domains, increasing the likelyhood that an update will get through. On the flip side, this process appears that it would result in a very slow spread of updates. It can easily take days, weeks, or months for a single machine to finally stumble upon a live domain.

The second method is to download the code via a peer-to-peer connection between infected hosts. As I understand it, the peer-to-peer mechanism has been active since revision C of Conficker has been in the wild. This mechanism allows an update to spread from system to system in a very rapid manner. Additionally, based on how the peer-to-peer mechanism works, it appears that blocking it is difficult, at best.

So what is the risk here? Seriously, is my computer destined to become a molten heap of slag, a spam factory, or possibly a zombie soldier in a botnet attack against foreign governments? Is all hope lost? Oh my , are we all going to die!

For the love of all things digital, pull it together! It's not as bad as it looks! First off all, if you consistently update your machines and keep your anti-virus up to date, chances of you being infected are very low. If you don't keep up to date, then perhaps you should start. At any rate, fire up a web browser and search for a Conficker scanner. Most of the major anti-virus vendors have one. Make sure you're familiar with the company you're downloading the scanner from, though, a large number of scam sites have popped up since Conficker hit the mainstream media.

If you're a network admin, you have a bigger job. First, I'd recommend any windows machines you are responsible for are patched. Yes, that includes those machines on that private network that is oh-so impossible to get to. Conficker can spread via samba shares and USB keys as well. Next, try scanning your network for infections. There are a number of Conficker scanners out there now thanks to the Honeynet Project and Dan Kaminsky. I have personally used both the proof-of-concept python scanner, as well as the latest version of nmap.

If you're using nmap, the following command line works quite well and is incredibly fast :

nmap -sC --script=smb-check-vulns --script-args=safe=1 -p139,445 \
-d -PN -n -T4 --min-hostgroup 256 --min-parallelism 64 \
-oA conficker_scan

Finally, as a network admin, you should probably have some sort of Intrusion Detection System (IDS) in place. Snort is an open source IDS that works quite well and has a large community following. IDS signatures exist to detect all known variants of Conficker.

So calm down, take a deep breath, and don't worry. I find it extremely unlikely that April 1 will result in anything more than a blip in network activity. Instead, concentrate on detection and patching. Conficker isn't Skynet.... Yet.

I spoke with a good friend of mine last week about his recent trip to NANOG. While he was there, he listened to a talk about detecting DNS cache poisoning. However, this was detection at the authoritative server, not at the cache itself. This is a bit different than detection at a cache because most cache poisoning will happen outside of your domain.

I initially wrote about the Kaminsky DNS bug a while back, and this builds somewhat on that discussion. When a cache poisoning attack is underway, the attacker must spoof the source IP of the DNS response. From what I can tell, this is because the resolver is told by the root servers who the authoritative server is for the domain. Thus, if a response comes back from a non-authoritative IP, it won't be accepted.

So let's look at the attack briefly. The attacker starts requesting a large number of addresses, something to the tune of a.example.com, b.example.com, etc. While those packets are being sent, the attacker sends out the responses with the spoofed headers. Since we are now guessing both the QID *and* the port, we miss a lot because the port is incorrect.

When the server receives a packet on a port that is not expecting data, it responds with an ICMP message, "Destination Port Unreachable." That ICMP message is sent to the source IP of the packet, which is the spoofed authoritative IP. This is known as ICMP backscatter.

Administrators of authoritative name servers can monitor for ICMP backscatter and identify possible cache poisoning attacks. In most cases, there is nothing that can be done directly to mitigate these attacks, but it is possible to identify the cache being attacked and notify the admin. Cooperation between administrators can lead to a complete mitigation of the attack and protection of clients who may be harmed.

This is an excellent example of the type of data you can identify simple through passive monitoring on your local network.