Archive for the ‘1-emerg’ category

Poor Man’s DLP

January 11th, 2010

Greets all,

I’m in New Orleans at the SANS Encryption & DLP conference giving a talk titled “Poor Man’s Data Leak Prevention”. I promised the attendees a copy of the slides, so here ya go.

poor-mans-dlp

It is all about key management

January 7th, 2010

I’ve written in the past about how when encryption fails, key management is usually to blame. You may have seen the news that SySS has figured out how to simultaneously crack open FIPS 140-2 level 2 USB drives from Kinston, SanDisk and Verbatim. If you have not heard about this yet, read on. The crack would be comical if it was not so scary easy.

All the USB drives in question use 256 bit AES to secure the partition. They also use hardware to perform the encryption process. The flaw is in the front end software that performs the authentication. SySS found that when a successful password was entered, a numeric string was sent to the drive to encrypt/decrypt the data. So far, so good. The flaw is that the exact same numeric string is used by all the drives, regardless of password.  In other words, it appears that the same key is always being used to protect every single drive. Create a little software magic to send that string to any of the above mentioned drives, and you will gain access to the data. No knowledge of the password is required, nor is brute forcing. Just send the magick string and “POOF!” the drive is open.
This reminds me of the hack a European group found with a military grade USB drive a few years back. What they figured out is that a successful password triggered a specific pin combination. Trigger the pin with a battery and you have access to the drive.
Of course this creates big problems for the end user community. The marketing material on the drives looks good. They are using the right algorithm, meeting the right NIST spec, and yet the drives are just short of useless. How do you know which drives are actually safe? For me, it goes back to a comment an old mentor once made to me, “bleeding edge and cryptography don’t mix”. Guess the only way to know for sure is to let others vet it for a few years first.

WinHelp 1.0 Released

January 1st, 2010

I just released version 1.0 of WinHelp for the iPhone and iTouch. A good sign for me was that even before the tool was released I found myself referring to it. ;)

A couple of screen shots to give you a feel for the tool:

If you want to learn more, check out Mobile Security Hack.

IP Lookup Completed

December 10th, 2009

Just finished a new tool called IP Lookup that I’ve submitted to the Apple App store. With any luck it will see the light of day over the next week or so.

I know, there are plenty of TCP/UDP port references out there. I’ve tried to make this the most complete list available. There are currently over 12,000 entries and I’m still growing the list.

One of the features I’m really psyched about is the real time searching. As you type in what you are looking for, the list is filtered in real time so you can see the results.

screenshot-2

More info can be found at my Mobile Security Hack site.

And now back to your commercial free educational material. ;)

Call Me Crazy…

December 1st, 2009

but I’ve agreed to do a Podcast with the PaulDotCom crew. Oh let the insanity ensue.

It will be this Friday at 8:30 EST. More details can be found here:

http://www.pauldotcom.com/

If you have never tuned in, you have no idea what you are missing. Sure network security is serious business, but you have to have a sense of humor to keep from going over the edge. The podcasts are a great source of news and info with a good mixture of laughs added on the side. Think “Monty Python meets Dick Cheney… with beer” and you’ll get the idea. ;)

Hope you tune in!

I don’t know everything, and that’s OK

November 21st, 2009

Over the last few days I ran a challenge to see who could write a tcpdump/Windump filter to grab packets with the Window Scale option set. It was a bit of a brain twister. It was one of those problems that you start off thinking is easy, but then realize is very hard. You then start questioning if you are on the right track because it can’t possibly be as complex as it seems to be. I was specifically trying to push the envelope a bit on this one.

In the challenge I stated that folks should post their thoughts/answers in the comments section. Only one person was willing to do so, while everyone else contacted me via e-mail. At first I thought it was a privacy concern, but then I remembered that I let users pick any alias they want for a screen name. Folks had some really good ideas, but I think they were afraid to come across as too much of  a “newbie” in a public forum. I’ve seen the same thing in classroom settings where I will teach a topic, ask if there are questions, no one will raise their hand, but at the end of the day I have a line in front of my desk.

I hit a bit of a milestone this year in that I realized I’ve been in the industry for over 20 years. To give you an idea how long that is in Internet time, one of my first gigs was helping to convert a government contractor over from the “host file system” to this brand new technology called “Domain Name Services”. I remember when Gopher was the slickest kid on the block. Experienced first hand how AOL connecting to the Internet dramatically changed the landscape of computer security. I’ve worked with such greats as Robert Morris Sr. and Alan Paller. I’ve traded tip and tricks with thousands of the brightest minds via the SANS Institute. I’ve spent time consulting to The White House as well as a number of other government agencies.

And with all that said, I’m the first to admit that I by no means know everything. In fact, I fully recognize I still have far more to learn than I’ve already squirreled away in the little gray cells. Personally, I still run across stuff (like filtering for the WScale option) that I look at and say “How the heck have I missed that all these years?”.

One of the things the obsessive side of me loves about network security is that it is a bottomless pit. You can spend every waking moment reading blog/list posts, downloading tools, testing in the lab, and still not be able to wrap your brain around all of it. Network security is subtle and full of nuances. Everyone’s brain is wired differently, so some of these nuances are obvious, and others not so much. One of the cool things about sticking yourself out there is you get the benefit of other people’s brain chemistry. Clearly one of the biggest problems on the white hat side of the fence is that we do not exchange ideas/perspectives often enough. I think far too often ego holds us back.

Are there folks that think they know it all? Absolutely. Again, ego can be a tricky master. I’m reminded of those old t-shirts and posters that read: “Teenagers: Leave home while you still know everything!”. With network security, like most things in life, there is a barrier of enlightenment. On one side of the barrier, the pond seems small and you think you have a handle on it all. Once you break through however you recognize the vastness of the galaxy and just how far ahead that road still stretches.

So I’m proposing a 12 step geek program and I’ll be the first to climb on a soapbox and admit “I don’t know everything and I’m OK with that”. Part of the reason I gave Jeff second place is he came at the problem from a completely different approach and developed a solution I didn’t think of. In other words, by putting myself out there I received the benefit of his brain chemistry.

Like Jeff, everyone reading this draws on their own unique life experience and are fully capable of coming up with unique and innovative solutions as well. You’ll never know for sure however unless you check the ego gremlin and stick yourself out there.

</soapbox>

Chris

Cybersecurity Act of 2009 In-Depth – Part 2

September 11th, 2009

In yesterday’s post I covered the first half of the Cybersecurity Act of 2009. Here’s the write up on the second half of the bill.

Section 13: Cybersecurity competition and challenge

As the name implies, this sets up funding for a series of competitions to help identify the best and the brightest.

(a) IN GENERAL- The Director of the National Institute of Standards and Technology, directly or through appropriate Federal entities, shall establish cybersecurity competitions and challenges with cash prizes in order to–

(1) attract, identify, evaluate, and recruit talented individuals for the Federal information technology workforce; and

(2) stimulate innovation in basic and applied cybersecurity research, technology development, and prototype demonstration that have the potential for application to the Federal information technology activities of the Federal Government.

No red flags here. Prizes cannot exceed $1M without checks and balances kicking in. Don’t get your hopes up. That’s for an entire event, not one specific prize.

Section 14: Public-private clearinghouse

This section seems pretty benign, till you read it closely. Here’s the opening section:

(a) DESIGNATION- The Department of Commerce shall serve as the clearinghouse of cybersecurity threat and vulnerability information to Federal Government and private sector owned critical infrastructure information systems and networks.

Yawn. I see this as something you cannot mandate. If you can provide useful information, users will seek out what you have to say. If you simply reprint what has already been released as open source, then my Google news feed will probably get me the info faster and with a better interface. It is easy to want to ignore this section based on this opening statement, but please read a bit further:

(b) FUNCTIONS- The Secretary of Commerce–

(1) shall have access to all relevant data concerning such networks without regard to any provision of law, regulation, rule, or policy restricting such access;

What??? This to me is the ultimate power grab. So any network or system that can be deemed “critical infrastructure” has to let the commerce department have unfettered access to their network. This access is without regard to due process or the rule of law. “Relevant” is a highly subjective term that can be applied to anything.

So it comes back to that “critical infrastructure” description that we already stated is the judgment call of a single individual. Maybe Microsoft’s network should be deemed critical infrastructure, as they are the government’s primary desktop vendor. Perhaps Linux development servers should also be deemed “critical” as servers, appliances, and embedded technology is based on this platform. What about Anti-Virus and firewall vendors who supply products to the government? Internet service providers servicing government networks? Telco’s servicing government employees? Universities funded to develop cyber protection techniques? This can be an extremely slippery slope.

To me, this is probably the single most dangerous part of the bill.

Section 15: Cybersecurity risk management report

In short, this section requires the President to produce a report within one year that identifies:

(1) creating a market for cybersecurity risk management, including the creation of a system of civil liability and insurance (including government reinsurance); and

(2) requiring cybersecurity to be a factor in all bond ratings.

This item could be taken in a number of directions. If they are smart, they will look at the feasibility of voiding end user agreements so that software vendors must accept liability for the security failing in their product. Without liability, vendors have little motivation to architect in a security framework from product inception. It is much easier and cheaper to glue it on after paying customers have already encounter problems.

Section 16: Legal framework review and report

This section calls for the President’s office to review existing cybersecurity laws regarding:

the Federal statutory and legal framework applicable to cyber-related activities in the United States

In short, this is a review to see if the laws are still applicable or need updating.

Section 17: Authentication and civil liberties report

Here’s the entire section:

Within 1 year after the date of enactment of this Act, the President, or the President’s designee, shall review, and report to Congress, on the feasibility of an identity management and authentication program, with the appropriate civil liberties and privacy protections, for government and critical infrastructure information systems and networks.

I’m not sure what to make of this section. It reads like they want to find a single sign-on solution for government networks. If that is the case, I don’t understand the “appropriate civil liberties and privacy protections” statement. This implies an application that is geared more towards the general public. Jury is still out on this section as I have not seen any other opinions on it.

Section 18: Cybersecurity responsibility and authority

Here’s the section that everyone is freaking out about. The blurb:

The President–

(2) may declare a cybersecurity emergency and order the limitation or shutdown of Internet traffic to and from any compromised Federal Government or United States critical infrastructure information system or network;

Sounds bad, but think of it this way. When planes were crashing into building the President ordered the grounding of all commercial flights. I doubt there was a specific law giving him that specific authority, but given it was an emergency situation no one argued the point or considered it an abuse of power.

I see this provision as being similar. If it is confirmed that attackers have taken control of the power grid and are now systematically shutting it down, no one is going to fault the President for requiring those organizations to isolate themselves from the Internet at large. It may or may not actually fix the problem, but it would be an expected defense posture. This would occur with or without this provision in the bill.

So to me this section is a lot of hoopla about nothing. Some of the previously discussed sections are far scarier.

Another interesting point in this section:

(5) shall direct the periodic mapping of Federal Government and United States critical infrastructure information systems or networks, and shall develop metrics to measure the effectiveness of the mapping process

To some extent, this process has already started as part of the Trusted Internet Connect (TIC) program. I’m actually kind of surprised it is not already a requirement. It is possible this is already being done but that data was unavailable when the bill was written.

Section 19: Quadrennial cyber review

(a) IN GENERAL- Beginning with 2013 and in every fourth year thereafter, the President, or the President’s designee, shall complete a review of the cyber posture of the United States, including an unclassified summary of roles, missions, accomplishments, plans, and programs.

In short, each new president gets to provide commentary on how they think their predecessor performed with regards to cybersecurity. This report would be far more useful if it was required a year earlier. That way it would act as a briefing for the new President. It would give them a better idea of what is required going forward.

Section 20: Joint intelligence threat assessment

Specifies (yet another) annual report on cybersecurity to Congress. Nothing to see here. Move along.

Section 21: International norms and cybersecurity deterrence measures

Here’s the clip:

The President shall–

(1) work with representatives of foreign governments–

(A) to develop norms, organizations, and other cooperative activities for international engagement to improve cybersecurity; and

(B) to encourage international cooperation in improving cybersecurity on a global basis

I see this as being more the role of the Department of Justice. What is needed is better interaction between law enforcement across international borders, not PR snippets and posturing. Think of it this way, what would be more effective in deterring physical crimes over state borders, frequent interaction between state law enforcement agencies, or frequent interaction between Governors?

Section 22: Federal secure products and services acquisitions board

To me, this is probably one of the most positive sections of the bill. Here’s the blurb:

(a) ESTABLISHMENT- There is established a Secure Products and Services Acquisitions Board. The Board shall be responsible for cybersecurity review and approval of high value products and services acquisition and, in coordination with the National Institute of Standards and Technology, for the establishment of appropriate standards for the validation of software to be acquired by the Federal Government.

In short, the government would be using its combined purchasing power to enforce security standards for all software purchases. This can have a profound impact on the commercial industry. Vendors love to complain that it is too expensive to ship secured software. Now if they wish to sell to the government, they will have to meet the appropriate NIST standards. Most likely the secured software would be available for commercial purchase as well. So out of the box you would end up with a more secure product.

Again, I see this as an extremely positive requirement. While vendors may grumble about it, as customers we would all benefit.

Section 23: Definitions

This is simply a definition of terms used in the bill. All are either common terms (like “Internet”) or described in earlier sections.

Exec Summary

There are things to love as well as fear in this bill. It increases funding for cybersecurity research as well as leverages the government’s buying power to generate more secure software for everyone. At the same time it attempts to circumvent established processes (as well as rules of law) that have the potential to make the cybersecurity situation worse rather than better. The bill is currently being reviewed by the Senate Committee on Commerce, Science, and Transportation. Now is the time to voice any praises or concerns you may have.

Cybersecurity Act of 2009 In-Depth – Part 1

September 10th, 2009

There have been quite a few articles on the Cybersecurity Act of 2009. Most have focused on the section that would give the president the power to “shutdown the Internet”. But are there other things in this bill you should be even more concerned about? Is there anything actually useful in the bill? In this two part post I’ll take you through the bill section by section.

The first two sections are simply the index and the findings. One notable quote from section 2:

(1) America’s failure to protect cyberspace is one of the most urgent national security problems facing the country.

This sets the tone for the rest of the section and I have to say I agree with the statement. Security wise we truly are in worse shape than most people want to believe.

Section 3: Cybersecurity advisory panel

These two quotes really say it all:

(a) IN GENERAL- The President shall establish or designate a Cybersecurity Advisory Panel.

(c) DUTIES- The panel shall advise the President on matters relating to the national cybersecurity program and strategy

I have mixed feelings regarding these points. I think that cybersecurity is important enough to deserve high-level visibility. However this bill goes hand in hand with S. 788, a bill to create the position of Cybersecurity Advisor, and H.R. 1910, a bill to create the position of Chief Technology Officer. Both of these positions would report directly to the president, so it seems more useful to have the panel fall under these two rolls in the national org chart. May just be semantics, but one of the issues we have today is parallel tenure with no clear ownership of problems. If all three bills pass I see a higher chance of creating conflicts rather than resolutions.

Section 4: Real time cybersecurity dashboard

I’ve seen little attention given to this item, but there is an easily dismissible statement made in this section:

The Secretary of Commerce shall

(1) in consultation with the Office of Management and Budget, develop a plan within 90 days after the date of enactment of this Act to implement a system to provide dynamic, comprehensive, real-time cybersecurity status and vulnerability information of all Federal Government information systems and networks managed by the Department of Commerce;

A couple of points here, why just the department of commerce? If this will be a truly useful resource, why not extend it’s use beyond this one government office? Also, the statement is a bit vague. This could be as ineffectual as the National Threat level or a subset of the data provided by sites such as DShield or Homeland Security’s Open Source Infrastructure Report. Either way I see this as a long-term failure.

Section 5: State and regional cybersecurity program

Here’s the focus of this section:

(a) CREATION AND SUPPORT OF CYBERSECURITY CENTERS- The Secretary of Commerce shall provide assistance for the creation and support of Regional Cybersecurity Centers for the promotion and implementation of cybersecurity standards. Each Center shall be affiliated with a United States-based nonprofit institution or organization, or consortium thereof, that applies for and is awarded financial assistance under this section.

Sounds good on the first read, but what’s up with the “affiliated with… nonprofit organizations” section? We could easily end up with a non-centralized system with no clear point of contact for their target audience. So if I need help with cybersecurity, I should go to… The Jimmy Fund? Farm Aid? Or maybe it’s the Tennessee Elephant Sanctuary?

Personally, I think these centers should be affiliated with InfraGard. They are established in nearly every state, already have a long history of community outreach, and are already focused on dealing with cybersecurity issues. My guess is that the commerce department wants complete control, while InfraGard is already associated with the FBI.

So what is the goal of creating these centers?

(b) PURPOSE- The purpose of the Centers is to enhance the cybersecurity of small and medium sized businesses in United States

This is an admirable goal. Due to lack of resources, small and medium size businesses are struggling the most. Probably the only demographic that is larger would be home users. If we could take steps to support these organizations, it would go a long way towards fortifying our national security posture.

The centers would support small and medium businesses by:

(1) disseminate cybersecurity technologies, standard, and processes based on research by the Institute for the purpose of demonstrations and technology transfer;

(2) actively transfer and disseminate cybersecurity strategies, best practices, standards, and technologies to protect against and mitigate the risk of cyber attacks to a wide range of companies and enterprises, particularly small- and medium-sized businesses; and

(3) make loans, on a selective, short-term basis, of items of advanced cybersecurity countermeasures to small businesses with less than 100 employees.

Again, I see these activities as a great fit for InfraGard. Deployment would be expedited as there is already a national structure. These would dramatically cut the curve on making these resources available.

Section 6: NIST standards development and compliance

The bill looks to NIST to develop security standards for all government agencies:

(a) IN GENERAL- Within 1 year after the date of enactment of this Act, the National Institute of Standards and Technology shall establish measurable and auditable cybersecurity standards for all Federal Government, government contractor, or grantee critical infrastructure information systems and networks

NIST is already responsible for setting standards. In fact their security documents are considered to be some of the best in the industry. Per the Information Technology Reform Act of 1996, NIST is already charged with developing Federal Information Processing Standards (FIPS).

I’m not a lawyer, but I don’t see anything in this section that has not already been specified by earlier bills except this tid bit under “(d) Compliance enforcement”:

(2) shall require each Federal agency, and each operator of an information system or network designated by the President as a critical infrastructure information system or network, periodically to demonstrate compliance with the standards established under this section.

I’m honestly not sure if the President currently has the power to (arbitrarily?) designate any network or system as “critical” and thus subject to this section. I prefer specific definitions versus subjectively trusting the judgment of a single individual. This way we are covered in both directions, from systems that should have been included but were missed, as well as systems that don’t really belong on the list.

Section 7: Licensing and certification of cybersecurity professionals

This section really scares me as it has the potential to do more harm than good. Here’s the description:

(a) IN GENERAL- Within 1 year after the date of enactment of this Act, the Secretary of Commerce shall develop or coordinate and integrate a national licensing, certification, and periodic recertification program for cybersecurity professionals.

To me, someone who has no idea of the scope of what is needed to address the problem wrote this section. Cybersecurity is not a single discipline. There are experts that focus on Malware analysis, perimeter security, packet decoding and intrusion analysis, incident handling, host specific security, auditing, forensics, wireless, databases, and the list goes on and on. A national certification and licensing program would end up being one of the following:

  1. So general it really does not mean anything
  2. So difficult “certified” resources would be hard to come by

Because of the diversity of the cybersecurity field, there really is no middle ground. This section then goes on to say:

(b) MANDATORY LICENSING- Beginning 3 years after the date of enactment of this Act, it shall be unlawful for any individual to engage in business in the United States, or to be employed in the United States, as a provider of cybersecurity services to any Federal agency or an information system or network designated by the President, or the President’s designee, as a critical infrastructure information system or network, who is not licensed and certified under the program.

Wait a minute. Let’s just take one glaring example. Alan Paller is the Director of Research at SANS, was quoted in this bill (Section 2, #8), and is one of my personal heroes in this industry. He’s provided council to the White House and Congress multiple times. He’s one of those unique individuals that can mediate the gap between folks that speak different languages (geeks, CFO, COO, etc.). While he knows the industry, he’s not the kind of guy that spends time writing Nessus plug-ins or decoding TCP attack streams. Is it truly the intent of this bill to loose resources like Alan if they choose not to certify?

There is a pattern here however. Like so many line items before it, this section puts control in the hands of the commerce department. So I personally think this is less about ensuring we have skilled personnel supporting network security, and more about grabbing power.

Section 8: Review of NTIA domain name contracts

This is another scary section:

(a) IN GENERAL- No action by the Assistant Secretary of Commerce for Communications and Information after the date of enactment of this Act with respect to the renewal or modification of a contract related to the operation of the Internet Assigned Numbers Authority, shall be final until the Advisory Panel–

(1) has reviewed the action;

(2) considered the commercial and national security implications of the action; and

(3) approved the action.

The Internet Assigned Numbers Authority (IANA) is run by The Internet Corporation for Assigned Names and Numbers (ICANN). This is a non-profit international organization that is responsible for guiding (not implementing) high-level operations of the Internet. They take guidance from a number of organizations, including the Internet Engineering Task Force (IETF) who defines the standards for Internet communications. The IETF is an international organization made up of everyone from individual researchers to vendors.

To me, this section sounds like an attempt to bring financial pressure on these organizations. Again, this seems to be an attempt to consolidate more power under the department of commerce. Especially when you combine it with section 9.

Section 9: Secure domain name addresses system

Here’s the clip:

(a) IN GENERAL- Within 3 years after the date of enactment of this Act, the Assistant Secretary of Commerce for Communications and Information shall develop a strategy to implement a secure domain name addressing system. The Assistant Secretary shall publish notice of the system requirements in the Federal Register together with an implementation schedule for Federal agencies and information systems or networks designated by the President, or the President’s designee, as critical infrastructure information systems or networks.

As mentioned in the last section, developing Internet standards in the role of the IETF, not the commerce department. Further, we already have standards to secure the domain name structure (DNSSEC) as well as routing and the IP addressing scheme (sBGP). The problem is their deployment has been extremely slow. What we need is deployment of the existing standards, not competitive ones developed outside of the accepted IETF process.

This section then goes on to say:

(b) COMPLIANCE REQUIRED- The President shall ensure that each Federal agency and each such system or network implements the secure domain name addressing system in accordance with the schedule published by the Assistant Secretary.

OK here’s the problem. In order to secure IP and DNS the solution has to be implemented globally. That’s part of the reason why it has been taking so long. If the federal government today deployed DNSSEC and sBGP it would do little to prevent domain name hijacking or route redirection because attackers could simply work outside of the government’s perimeter.

I have to say I share the frustration in this area. Both DNSSEC and sBGP have been around for 10 years. I think we need to suck it up on the disruptions that may be caused by deployment and just get the job done. Perhaps ICANN needs a fire lit under their butts to create some forward motion. I’m just not convinced these two sections are the way to go about it.

Section 10: Promoting cybersecurity awareness

You knew a PR campaign has to be included in here somewhere, right? Here’s the blurb:

The Secretary of Commerce shall develop and implement a national cybersecurity awareness campaign

Not sure how useful this will be because the news feeds are already full of stories that describe our current state of security. I see this as having the potential to be silly rather than informative. I have these visions of walking into my kid’s school and seeing a poster that states “Billy Bytes Says Don’t Be A H4X0r”. OK, hopefully that will never happen, but you never know. ;)

Section 11: Federal cybersecurity research and development

Here’s the initial statement:

(a) FUNDAMENTAL CYBERSECURITY RESEARCH- The Director of the National Science Foundation shall give priority to computer and information science and engineering research to ensure substantial support is provided to meet the following challenges in cybersecurity:

This section dumps a lot of money into the research and development of cybersecurity techniques. It amends existing bills to increase spending by $265M in 2010, to over $310M by 2014. There are already other programs that fund cybersecurity research, but provided the funds are managed appropriately I see this as being helpful to the cause.

Section 12: Federal cyber scholarship for service program

Here’s the clip:

(a) IN GENERAL- The Director of the National Science Foundation shall establish a Federal Cyber Scholarship-for-Service program to recruit and train the next generation of Federal information technology workers and security managers.

This is no different than many other “scholarship for service” programs. I see this as being beneficial to both the student as well as the government. $50M has been allocated to the program, increasing to $70M by 2014.

Summary

That’s it for now. Tomorrow I’ll post the last half of the bill.

If you can read this, you don’t work for SANS

August 4th, 2009

Anyone that has trained with me can tell you I’m real big on being able to read your own detects. While we have plenty of security devices that try to accurately describe what they think they see on the wire, they are programmed by humans and humans make mistakes. Try and automate the process and the mistakes become compounded. Even Cisco has backed off a bit on their grandiose claims of what a self defending network is actually capable of. Nothing replaces having a skilled analyst reviewing the findings.

Good help is hard to find

Of course the keyword in that last comment is skilled. I’ve dealt with plenty of senior security folks that have never seen a decode of an IP packet, let alone can tell you what a legit IP session should look like. One of the problems is when we need training we usually turn to the vendors. Vendors tend to focus on their pretty GUI, not what’s going on behind the scenes.

In a previous life I owned an ISP and had some very entertaining abuse reports submitted. One of my personal favorites was an admin reporting that one of my systems was “sending hostile ICMP packets” to one of his systems. When I reviewed my logs, I noted that one of my routers was in fact sending him ICMP host unreachable messages. This would happen every time his host probed the RPC port of an IP address that was not in use. I wrote back and explained that if his system would simply stop probing for non-existent systems, my router would stop telling him the host is off-line.

Another admin (at a rather large, well known company I might add) informed me that one of my systems was attacking him with Code Red via e-mail. If you remember Code Red, it only attacked IIS Web servers via HTTP. The “attacks” in question were users subscribed to a mailing list. Folks were talking about how to write good intrusion signatures to properly catch Code Red. If that was not ironic enough, the payload of the decode he sent me as evidence explained that the attacks were only HTTP based. If that twist is still not enough to make you chuckle, he later admitted that he was the one of the people subscribed to that list. :D

The more things change the more they stay the same

My hosting provider Host Monster (a subsidiary of Blue Host) has put a filter in place blocking all access to the SANS Institute mail server (SysAdmin, Audit, Network, Security Institute; provides computer security training), The Internet Storm Center (daily diary of Internet security threats) and DShield (an early warning system for Internet threats). I contacted support and they confirmed they are filtering these sites. I was unable to find out why beyond “due to suspicious activity”.

I know the folks that maintain the SANS and Dshield servers. They are hard core security folks with a serious clue. When I first signed up with my hosting provider I was impressed with the knowledge level of their support personnel. Lately however, I’ve found them to be lacking in even the basics. While I’m left to guess as to what actually caused the ban, I’m inclined to think that someone at Host Monster (or possibly Blue Host) saw an alert but didn’t have the skills to figure out its a false positive.

Communication is a two way street

Blue Host claims 1.5 million hosted sites through all of their holdings. So they now have 1.5 million clients that can’t:

  • Receive real time blocking alerts of malicious IP’s
  • Receive assessments on current Internet threats
  • Receive info on what’s going on in the security industry

So while attempting to protect themselves is a positive thing, the implementation has had a negative effect on the security of their clients.

How to verify a detect

So let’s pull something positive out of all of this and identify the proper procedure for verifying a security alert. We first need to start with good gear. Do not even consider an intrusion detection or prevention system that does not include:

  • Access to the signature language
  • Full decode of suspect packets

Without these features you are shooting in the dark.

Step 1: Understand the attack

When an alert gets triggered, make sure you understand the attack mechanism. What ports or services does it go after? Are there any known signatures? If you Google the attack’s name followed by the key words “false positive” and “spoofed”, does anything come up?

Step 2: Understand your intrusion system

No security product is perfect. They all have weaknesses or limitations. Does your intrusion system maintain state? If so, is it all the time or just some of the time? Does it properly validate CRC fields? How does it deal with fragmented traffic? Is it known to generate false positives? If so, are the false positives limited to only certain signatures or protocols, or is it all of the time?

Step 3: Sanity check the alert

Sometimes false positives can be weeded out from the limited amount of info presented in an alert. For example does the alert claim to have detected an HTTP attack coming from TCP/80 instead of going to it? If so, there is an obvious problem with the signature generating the alert.

Step 4: Check the signature

Some signatures are written very specifically so that there is little chance of a false positive. Some are more general however so its possible to have false positive fall out. Review the signature that generated the alert and make a judgement call. Does the signature check 3-4 different conditions or ten or more? Obviously the more parameters we are checking, the less likely we are to get a false positive.

Step 5: Check the decode

If you understand the attack pattern, you should already have an expectation of what will be in the attack decode. Does the packet match your expectations? I’ve seen plenty of false positives generated by people reading info on a Web site describing an HTTP based attack. These are easy to distinguish due to the extra HTML, proper agent and referrer fields, etc. In short, if the packet does not match a known decode of the real attack, figure out why.

Step 6: Research the source

I always take the time to make sure I understand who is sitting behind the source IP address. Sometimes this can go a long way towards identifying whether I can trust the alert. I’m reminded of a friend that banned a number of IP addresses his intrusion system had identified as hostile. Shortly after he started noticing that parts of the Internet were no longer reachable. Turns out someone spoofed a series of attacks from the IP addresses of the root name servers. Had he taken the time to look up the IP addresses first, he most certainly would not have blocked them.

Exec Summary

Blocking known to be hostile IP addresses can certainly be beneficial to security, but it must be implemented with caution. At the core of any network security system must be a knowledgeable security expert with good common sense. If that component is missing, the whole structure can fall apart like a house of cards.

Update: Since posting this I’ve found that Host Monster (Blue Host) is blocking access to one or more Cisco servers as well. Guess the list continues…

AES is becoming very close to broken

July 30th, 2009

In earlier posts I discussed what’s wrong with WPA and why its always a bad idea to base a standard around a single method of encryption, even AES. Bruce Schneier posted to his blog today regarding a new attack against AES. In short, the paper he references identifies how to dramatically reduce the number of guesses required to retrieve a key. While its not practical today for a basement hack to perform the attack, its still nasty stuff.

The attack in question is what is referred to as a related key attack. This requires the attacker to have some level of knowledge of the plain text secured by multiple related keys. In other words, we need to already know a bit of what is being protected and where to look for it.

This is a serious problem when you are talking about VPNs or wireless, because we are using it to secure IP traffic. IP uses some pretty consistent values:

  • Byte 0 contains the IP version (usually 4) and the size of the IP header (usually 20 bytes)
  • Byte 1 contains the type of service field (usually not used so set to 0)
  • Bytes 2 & 3 contain the total length field (a consistent value for traffic like ARP packets if you know the OS)
  • Byte 8 contains the TTL (a consistent value on a per OS basis)
  • Bytes 12-15 contain the source IP address (a consistent value for each specific system)

And that’s just the IP header…

So when we protect traffic on the wire, related key attacks can be particularly evil because there are many repetitive values to work with.

So what should you do? I’ll fall back on the same advice I gave in those earlier posts I referenced above. Make sure you have more options than just a single encryption algorithm, just in case things get a whole lot worse.