Thursday, February 23, 2017

SHA-1 is dead, long live SHA-1!

Unless you’ve been living under a rock, you heard that some researchers managed to create a SHA-1 collision. The short story as to why this matters is the whole purpose of a hashing algorithm is to make it impossible to generate collisions on purpose. Unfortunately though impossible things are usually also impossible so in reality we just make sure it’s really really hard to generate a collision. Thanks to Moore’s Law, hard things don’t stay hard forever. This is why MD5 had to go live on a farm out in the country, and we’re not allowed to see it anymore … because it’s having too much fun. SHA-1 will get to join it soon.

The details about this attack are widely published at this point, but that’s not what I want to discuss, I want to bring things up a level and discuss the problem of algorithm deprecation. SHA-1 was basically on the way out. We knew this day was coming, we just didn’t know when. The attack isn’t super practical yet, but give it a few years and I’m sure there will be some interesting breakthroughs against SHA-1. SHA-2 will be next, which is why SHA-3 is a thing now. At the end of the day though this is why we can’t have nice things.

A long time ago there weren’t a bunch of expired standards. There were mostly just current standards and what we would call “old” standards. We kept them around because it was less work than telling them we didn’t want to be friends anymore. Sure they might show up and eat a few chips now and then, but nobody really cared. Then researchers started to look at these old algorithms and protocols as a way to attack modern systems. That’s when things got crazy.

It’s a bit like someone bribing one of your old annoying friends to sneak the attacker through your back door during a party. The friend knows you don’t really like him anymore, so it won’t really matter if he gets caught. Thus began the long and horrible journey to start marking things as unsafe. Remember how long it took before MD5 wasn’t used anymore? How about SSL 2 or SSHv1? It’s not easy to get rid of widely used standards even if they’re unsafe. Anytime something works it won't be replaced without a good reason. Good reasons are easier to find these days than they were even a few years ago.

This brings us to the recent SHA-1 news. I think it's going better this time, a lot better. The browsers already have plans to deprecate it. There are plenty of good replacements ready to go. Did we ever discuss killing off md5 before it was clearly dead? Not really. It wasn't until a zero day md5 attack was made public that it was decided maybe we should stop using it. Everyone knew it was bad for them, but they figured it wasn’t that big of a deal. I feel like everyone understands SHA-1 isn’t a huge deal yet, but it’s time to get rid of it now while there’s still time.

This is the world we live in now. If you can't move quickly you will fail. It's not a competitive advantage, it's a requirement for survival. Old standards no longer ride into the sunset quietly, they get their lunch money stolen, jacket ripped, then hung by a belt loop on the fence.

Sunday, February 12, 2017

Reality Based Security

If I demand you jump off the roof and fly, and you say no, can I call you a defeatist? What would you think? To a reasonable person it would be insane to associate this attitude with being a defeatist. There are certain expectations that fall within the confines of reality. Expecting things to happen outside of those rules is reckless and can often be dangerous.

Yet in the universe of cybersecurity we do this constantly. Anyone who doesn’t pretend we can fix problems is a defeatist and part of the problem. We just have to work harder and not claim something can’t be done, that’s how we’ll fix everything! After being called a defeatist during a discussion, I decided to write some things down. We spend a lot of time trying to fly off of roofs instead of looking for practical realistic solutions for our security problems.

The way cybersecurity works today someone will say “this is a problem”. Maybe it’s IoT, or ransomware, or antivirus, secure coding, security vulnerabilities; whatever, pick something, there’s plenty to choose from. It’s rarely in a general context though, it will be sort of specific, for example “we have to teach developers how to stop adding security flaws to software”. Someone else will say “we can’t fix that”, then they get called a defeatist for being negative and it’s assumed the defeatists are the problem. The real problem is they’re not wrong. It can’t be fixed. We will never see humans write error free code, there is no amount of training we can give them. Pretending it can is what’s dangerous. Pretending we can fix problems we can’t is lying.

The world isn’t fairy dust and rainbows. We can’t wish for more security and get it. We can’t claim to be working on a problem if we have no clue what it is or how to fix it. I’ll pick on IoT for a moment. How many security IoT “experts” exist now? The number is non trivial. Does anyone have any ideas how to understand the IoT security problems? Talking about how to fix IoT doesn’t make sense today, we don’t even really understand what’s wrong. Is the problem devices that never get updates? What about poor authentication? Maybe managing the devices is the problem? It’s not one thing, it’s a lot of things put together in a martini shaker, shook up, then dumped out in a heap. We can’t fix IoT because we don’t know what it even is in many instances. I’m not a defeatist, I’m trying to live in reality and think about the actual problems. It’s a lot easier to focus on solutions for problems you don’t understand. You will find a solution, those solutions won’t make sense though.

So what do we do now? There isn’t a quick answer, there isn’t an easy answer. The first step is to admit you have a problem though. Defeatists are a real thing, there’s no question about it. The trick is to look at the people who might be claiming something can’t be fixed. Are they giving up, or are they trying to reframe the conversation? If you declare them a defeatist, the conversation is now over, you killed it. On the other side of the coin, pretending things are fine is more dangerous than giving up, you’re living in a fantasy. The only correct solution is reality based security. Have honest and real conversations, don’t be afraid to ask hard questions, don’t be afraid to declare something unfixable. An unfixable problem is really just one that needs new ideas.

You can't fly off the roof, but trampolines are pretty awesome.

I'm @joshbressers on Twitter, talk to me.

Monday, February 6, 2017

There are no militant moderates in security

There are no militant moderates. Moderates never stand out for having a crazy opinion or idea, moderates don’t pick fights with anyone they can. Moderates get the work done. We could look at the current political climate, how many moderate reasonable views get attention? Exactly. I’m not going to talk about politics, that dumpster fire doesn’t need any more attention than it’s already getting. I am however going to discuss a topic I’m calling “security moderates”, or the people who are doing the real security work. They are sane, reasonable, smart, and actually doing things that matter. You might be one, you might know one or two. If I was going to guess, they’re a pretty big group. And they get ignored quite a lot because they're too busy getting work done to put on a show.

I’m going to split existing security talent into some sort of spectrum. There’s nothing more fun than grouping people together in overly generalized ways. I’m going to use three groups. You have the old guard on one side (I dare not mention left or right lest the political types have a fit). This is the crowd I wrote about last week; The people who want to protect their existing empires. On the other side you have a lot of crazy untested ideas, many of which nobody knows if they work or not. Most of them won’t work, at best they're a distraction, at worst they are dangerous.

Then in the middle we have our moderates. This group is the vast majority of security practitioners. The old guard think these people are a bunch of idiots who can’t possibly know as much as they do. After all, 1999 was the high point of security! The new crazy ideas group thinks these people are wasting their time on old ideas, their new hip ideas are the future. Have you actually seen homomorphic end point at rest encryption antivirus? It’s totally the future!

Now here’s the real challenge. How many conferences and journals have papers about reasonable practices that work? None. They want sensational talks about the new and exciting future, or maybe just new and exciting. In a way I don’t blame them, new and exciting is, well, new and exciting. I also think this is doing a disservice to the people getting work done in many ways. Security has never been an industry that has made huge leaps driven by new technology. It’s been an industry that has slowly marched forward (not fast enough, but that’s another topic). Some industries see huge breakthroughs every now and then. Think about how relativity changed physics overnight. I won’t say security will never see such a breakthrough, but I think we would be foolish to hope for one. The reality is our progress is made slowly and methodically. This is why putting a huge focus on crazy new ideas isn’t helping, it’s distracting. How many of those new and crazy ideas from a year ago are even still ideas anymore? Not many.

What do we do about this sad state of affairs? We have to give the silent majority a voice. Anyone reading this has done something interesting and useful. In some way you’ve moved the industry forward, you may not realize it in all cases because it’s not sensational. You may not want to talk about it because you don’t think it’s important, or you don’t like talking, or you’re sick of the fringe players criticizing everything you do. The first thing you should do is think about what you’re doing that works. We all have little tricks we like to use that really make a difference.

Next write it down. This is harder than it sounds, but it’s important. Most of these ideas aren’t going to be full papers, but that’s OK. Industry changing ideas don’t really exist, small incremental change is what we need. It could be something simple like adding an extra step during application deployment or even adding a banned function to your banned.h file. The important part is explaining what you did, why you did it, and what the outcome was (even if it was a failure, sharing things that don’t work has value). Some ideas could be conference talks, but you still need to write things down to get talks accepted. Just writing it down isn’t enough though. If nobody ever sees your writing, you’re not really writing.  Publish your writing somewhere, it’s never been easier to publish your work. Blogs are free, there are plenty of groups to find and interact with (reddit, forums, twitter, facebook). There is literally a security conference every day of the year. Find a venue, tell your story.

There are no militant moderates, this is a good thing. We have enough militants with agendas. What we need more than ever are reasonable and sane moderates with great ideas, making a difference every day. If the sane middle starts to work together. Things will get better, and we will see the change we need.

Have an idea how to do this, let me know. @joshbressers on Twitter

Sunday, January 29, 2017

Everything you know about security is wrong, stop protecting your empire!

Last week I kept running into old school people trying to justify why something that made sense in the past still makes sense today. Usually I ignore these sort of statements, but I feel like I’m seeing them often enough it’s time to write something up. We’re in the middle of disruptive change. That means that the way security used to work doesn’t work anymore (some people think it does) and in the near future, it won’t work at all. In some instances will actually be harmful if it’s not already.


The real reason I’m writing this up is because there are really two types of leaders. Those who lead to inspire change, and those who build empires. For empire builders, change is their enemy, they don’t welcome the new disrupted future. Here’s a list of the four things I ran into this week that gave me heartburn.


  • You need AV
  • You have to give up usability for security
  • Lock it all down then slowly open things up
  • Firewall everything


Let’s start with AV. A long time ago everyone installed an antivirus application. It’s just what you did, sort of like taking your vitamins. Most people can’t say why, they just know if they didn't do this everyone would think they're weird. Here’s the question for you to think about though: How many times did your AV actually catch something? I bet the answer is very very low, like number of times you’ve seen bigfoot low. And how many times have you seen AV not stop malware? Probably more times than you’ve seen bigfoot. Today malware is big business, they likely outspend the AV companies on R&D. You probably have some control in that phone book sized policy guide that says you need AV. That control is quite literally wasting your time and money. It would be in your best interest to get it changed.


Usability vs security is one of my favorite topics these days. Security lost. It’s not that usability won, it’s that there was never really a battle. Many of us security types don’t realize that though. We believe that there is some eternal struggle between security and usability where we will make reasonable and sound tradeoffs between improving the security of a system and adding a text field here and an extra button there. What really happened was the designers asked to use the bathroom and snuck out through the window. We’re waiting for them to come back and discuss where to add in all our great ideas on security.


Another fan favorite is the best way to improve network security is to lock everything down then start to open it up slowly as devices try to get out. See the above conversation about usability. If you do this, people just work around you. They’ll use their own devices with network access, or just work from home. I’ve seen employees using the open wifi of the coffee shop downstairs. Don’t lock things down, solve problems that matter. If you think this is a neat idea, you’re probably the single biggest security threat your organization has today, so at least identifying the problem won’t take long.


And lastly let’s talk about the old trusty firewall. Firewalls are the friend who shows up to help you move, drinks all your beer instead of helping, then tells you they helped because now you have less stuff to move. I won’t say they have no value, they’re just not great security features anymore. Most network traffic is encrypted (or should be), and the users have their own phones and tablets connecting to who knows what network. Firewalls only work if you can trust your network, you can’t trust your network. Do keep them at the edge though. Zero trust networking doesn’t mean you should purposely build a hostile network.

We’ll leave it there for now. I would encourage you to leave a comment below or tell me how wrong I am on Twitter. I’d love to keep this conversation going. We’re in the middle of a lot of change. I won’t say I’m totally right, but I am trying really hard to understand where things are going, or need to go in some instances. If my silly ramblings above have put you into a murderous rage, you probably need to rethink some life choices, best to do that away from Twitter. I suspect this will be a future podcast topic at some point, these are indeed interesting times.

How wrong am I? Let me know: @joshbressers on Twitter.



Monday, January 23, 2017

Return on Risk Investment

I found myself in a discussion earlier this week that worked its way into return on investment topics. Of course nobody could really agree on what the return was which is sort of how these conversations often work out. It’s really hard to decide what the return on investment is for security features and products. It can be hard to even determine cost sometimes, which should be the easy number to figure out.

All this talk got me thinking about something I’m going to call risk investment. The idea here is that you have a risk, which we’ll think about as the cost. You have an investment of some sort, it could be a product, training, maybe staff. This investment in theory reduces your risk in some measurable way. The reduction of the risk is the return on risk investment. We like to think about these things in the context of money, but risk doesn’t exactly work that way. Risk isn’t something that can often be measured easily. Even incredibly risky behaviors can work out fine, and playing it safe can end horribly. Rather than try to equate everything to money, what if we ignored that for the moment and just worried about risk.

 First, how do you measure your risk? There isn’t a nice answer for this. There are plenty of security frameworks you can use. There are plenty of methodologies that exist, threat modeling, attack surface analysis, pen test reports, architecture reviews, automated scanning of products and infrastructure. There’s no single good answer to this question. I can’t tell you what your risk profile is, you have to decide how you’re going to measure this. What are you protecting? If it’s some sort of regulated data, there will be substantial cost in losing it, so this risk measurement is easy. It’s less obvious if you’re not operating in an environment that has direct cost to having an incident. It’s even possible you have systems and applications that pose zero risk (yeah, I said it).

 Assuming we have a way to determine risk, now we wonder how do you measure the return on controlling risk? This is possibly more tricky than deciding on how to measure your risk. You can’t prove a negative in many instances, there’s no way to say your investment is preventing something from happening. Rather than measure how many times you didn’t get hacked, the right way to think about this is if you were doing nothing, how would you measure your level of risk? We can refer back to our risk measurement method for that. Now we think about where we do have certain protections in place, what will an incident look like? How much less trouble will there be? If you can’t answer this you’re probably in trouble. This is the important data point though. When there is an incident, how do you think your counter measures will help mitigate damage? What was your investment in the risk?

 And now this brings us to our Return on Risk Investment, or RORI as I’ll call it, because I can and who doesn’t like acronyms? Here’s the thing to think about if you’re a security leader. If you have risk, which we all do, you must find some way to measure it. If you can’t measure something you don’t understand it. If you can’t measure your risk, you don’t understand your risk. Once you have your method to understand what’s happening, make note of your risk measurement without any sort of security measures in place, your risk with ideal (not perfect, perfect doesn't exist) measures in place, and your risk with existing measures in place. That will give you an idea of how effective what you’re doing is. Here’s the thing to watch for. If your existing measures are close to the risk level for no measures, that’s not a positive return. Those are things you either should fix or stop doing. Sometimes it’s OK to stop doing something that doesn’t really work. Security theater is real, it doesn’t work, and it wastes money. The trick is to find a balance that can show measurable risk reduction without breaking the bank.


How do you measure risk? Let me know: @joshbressers on Twitter.


Monday, January 16, 2017

What does security and USB-C have in common?

I've decided to create yet another security analogy! You can’t tell, but I’m very excited to do this. One of my long standing complaints about security is there are basically no good analogies that make sense. We always try to talk about auto safety, or food safety, or maybe building security, how about pollution. There’s always some sort of existing real world scenario we try warp and twist in a way so we can tell a security story that makes sense. So far they’ve all failed. The analogy always starts out strong, then something happens that makes everything fall apart. I imagine a big part of this is because security is really new, but it’s also really hard to understand. It’s just not something humans are good at understanding.

The other day this article was sent to me by @kurtseifried
How Volunteer Reviewers Are Saving The World From Crummy—Even Dangerous—USB-C Cables

The TL;DR is essentially the world of USB-C cables is sort of a modern day wild west. There’s no way to really tell which ones are good and which ones are bad, so there are some people who test the cables. It’s nothing official, they’re basically volunteers doing this in their free time. Their feedback is literally the only real way to decide which cables are good and which are bad. That’s sort of crazy if you think about it.

This really got me thinking though, it’s has a lot in common with our current security problems. We have a bunch of products and technologies. We don’t have a good way to tell if something is good or bad. There are some people who try to help with good information. But fundamentally most of our decisions are made with bad or incomplete data.

In the case of the cables, I see two practical ways out of this. Either have some sort of official testing lab. If something doesn’t pass testing, it can’t be sold. This makes sense, there are plenty of things on the market today that go through similar testing. If the products fails, it doesn’t get sold. In this case the comparable analogies hold up. Auto safety, electrical safety, hdmi; there are plenty of organizations that are responsible for ensuring the quality and safety of certain products. The cables would be no different.

A possible alternative to deal with this problem is you make sure every device will exist in a way that assumes bad cables are possible and deal with this situation in hardware. This would mean devices being smart enough to not draw too much power, or not provide too much power. To know when there will be some sort of failure mode and disconnect. There are a lot of possibilities here, and to be perfectly honest, no device will be able to do this with 100% accuracy. More importantly though, no manufacturer will be willing to add this functionality because it would add cost, probably a lot of cost. It’s still a remote possibility though, and for the sake of the analogy, we’re going to go with it.

The first example twisted to cybersecurity would mean you need a nice way to measure security. There would be a lab or organization that is capable of doing the testing, then giving some sort of stamp of approval. This has proven to be a really hard thing to do in the past. The few attempts to do this have failed. I suspect it’s possible, just very difficult to do right. Today Mudge is doing some of this with the CITL, but other than that I’m not really aware of anything of substance. It’s a really hard problem to solve, but if anyone can do it right, it’s probably Mudge.

This then leads us to the second possibility which is sort of how things work today. There is a certain expectation that an endpoint will handle certain situations correctly. Each endpoint has to basically assume anything talking to it is broken in some way. All data transferred must be verified. Executables must be signed and safely distributed. The networks the data flows across can’t really be trusted. Any connection to the machine could be an attacker and must be treated as such. This is proving to be very hard though and in the context of the cables, it’s basically the crazy solution. Our current model of security is the crazy solution. I doubt anyone will argue with that.

This analogy certainly isn’t perfect, but the more I think about it the more I like it. I’m sure there are problems thinking about this in such a way, but for the moment, it’s something to think about at least. The goal is to tell a story that normal people can understand so we can justify what we want to do and why. Normal people don’t understand security, but they do understand USB cables.


Do you have a better analogy? Let me know @joshbressers on Twitter.

Monday, January 9, 2017

Security Advice: Bad, Terrible, or Awful

As an industry, we suck at giving advice. I don’t mean this in some negative hateful way, it’s just the way it is. It’s human nature really. As a species most of us aren’t very good at giving or receiving advice. There’s always that vision of the wise old person dropping wisdom on the youth like it’s candy. But in reality they don’t like the young people much more than the young people like them. Ever notice the contempt the young and old have for each other? It’s just sort of how things work. If you find someone older and wiser than you who is willing to hand out good advice, stick close to that person. You won’t find many more like that.

Today I’m going to pick on security though. Specifically security advice directed at people who aren’t security geeks. Heck, some of this will probably apply to security geeks too, so let’s just stick to humans as the target audience. Of all our opportunities around advice, I think the favorite is blaming the users for screwing up. It’s never our fault, it’s something they did, or something wasn’t configured correctly, but still probably something they did. How many times have you dealt with someone who clicked a link because they were stupid. Or they opened an attachment because they’re an idiot. Or they typed a password in that web page because they can’t read. The list is long and impressive. Not once did we do anything wrong. Why would we though? It’s not like we made anyone do those things! This is true, but we also didn’t not make them do those things!

Some of the advice we expect people to listen to is good advice. A great example is telling someone to “log out” of their banking site when they’re done. That makes sense, it’s easy enough to understand, and nothing lights on fire if they forget to do this. We also like to tell people things like “check the URL bar”. Why would a normal person do this? They don’t even know what a URL is. They know what a bar is, it’s where they go to calm down after talking to us. What about when we tell people not to open attachments? Even attachments from their Aunt Millie? She promised that cookie recipe months ago, it’s about time cookies.exe showed up!

The real challenge we have is understanding what is good advice that would supplement a properly functional system. Advice and instructions do not replace a proper solution. A lot of advice we give out is really to mask something that’s already broken. The fact that we expect users to care about a URL or attachment is basically nuts. These are failures in the system, not failures with users. We should be investing our resources into solving the root of the problem, not yelling at people for clicking on links. Instead of telling users not to click on attachments, just don’t allow attachments. Expecting behavior from people rarely changes them. At best it creates an environment of shame but it’s more likely it creates an environment of contempt. They don’t like you, you don’t like them.

As a security practitioner, look for ways to eliminate problems without asking users for intervention. A best case situation will be 80% user compliance. That remaining 20% would require more effort to deal with than anyone could handle, and if your solution is getting people to listen, you need 100% all the time which is impossible for humans but not impossible for computers.

It’s like the old saying, an ounce of prevention is worth a pound of cure. Or if you’re a fan of the metric system, 28.34 grams of prevention is worth 453.59 grams of cure!

Do you have some bad advice? Lay it on me! @joshbressers on Twitter.