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Category Archives for "Security"

DNS Cookies and DDoS Attacks

DDoS attacks, particularly for ransom—essentially, “give me some bitcoin, or we’ll attack your server(s) and bring you down,” seem to be on the rise. While ransom attacks rarely actually materialize, the threat of DDoS overall is very large, and very large scale. Financial institutions, content providers, and others regularly consume tens of gigabits of attack traffic in the normal course of operation. What can be done about stopping, or at least slowing down, these attacks?

To answer, this question, we need to start with some better idea of some of the common mechanisms used to build a DDoS attack. It’s often not effective to simply take over a bunch of computers and send traffic from them at full speed; the users, and the user’s providers, will often notice machine sending large amounts of traffic in this way. Instead, what the attacker needs is some sort of public server that can (and will) act as an amplifier. Sending this intermediate server should cause the server to send an order of a magnitude more traffic towards the attack target. Ideally, the server, or set of servers, will have almost unlimited bandwidth, and bandwidth utilization characteristics that will make the attack appear Continue reading

Scanning for ClamAV 0day

Last week an 0day was released for ClamAV. Well, not really an 0day so much as somebody noticed idiotic features in ClamAV. So I scanned the Internet for the problem.

The feature is that the daemon listens for commands that tell it to do things like scan files. Normally, it listens only locally for such commands, but can be reconfigured to listen remotely on TCP port 3310. Some packages that include ClamAV sometimes default to this.

It's a simple protocol that consists of sending a command in clear text, like "PING", "VERSION", "SHUTDOWN", or "SCAN
So I ran masscan with the following command:

masscan 0.0.0.0/0 -p3310 --banners --hello-string[3310] VkVSU0lPTg==
Normally when you scan and address range (/0) and port (3310), you'd just see which ports are open/closed. That's not useful in this case, because it finds 2.7 million machines. Instead, you want to establish a full TCP connection. That's what the --banners option does, giving us only 38 thousand machines that successfully establish a connection. The remaining machines are large ranges on the Internet where firewalls are configured to respond with SYN-ACK, with the express purpose of frustrating port scanners.

But of those 38k machines, most are actually Continue reading

Establishing a confidential Service Boundary with Avaya’s SDN Fx

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Security is a global requirement. It is also global in the fashion in which it needs to be addressed. But the truth is, regardless of the vertical, the basic components of a security infrastructure do not change. There are firewalls, intrusion detection systems, encryption, networking policies and session border controllers for real time communications. These components also plug together in rather standard fashions or service chains that look largely the same regardless of the vertical or vendor in question. Yes, there are some differences but by and large these modifications are minor.

So the questions begs, why is security so difficult? As it turns out, it is not really the complexities of the technology components themselves, although they certainly have that. It turns out that the real challenge is deciding exactly what to protect and here each vertical will be drastically different. Fortunately, the methods for identifying confidential data or critical control systems are also rather consistent even though the data and applications being protected may vary greatly.

In order for micro-segmentation as a security strategy to succeed, you have to know where the data you need to protect resides. You also need to know how it flows through Continue reading

No, Musky, Feudalism is best for Mars

Recently, the press fawned all over Elon Musk's comments at a conference. Among them was Musk's claim that "direct democracy" would be the best system, where citizen's vote directly for laws, rather than voting for (corrupt) representatives/congressmen. This is nonsense. The best political system would be feudalism.

There is no such thing as "direct democracy". Our representatives in congress are only the first layer on top of a bureaucracy. Most rules that restrict us are not "laws" voted by congress but "regulations" decided by some bureaucrat.

Consider the BP Gulf Oil spill, as an example. It happened because oil companies got cozy with their regulators, the minerals Management Service (MMS), part of the Department of the Interior. The bureaucrats had a dual mandate: to protect the environment, and to promote economic activity. Oil companies lobbied them to risk the environment in favor of profits.

Consider  Obamcare's controversial mandate that health insurers must pay for abortions. This was not part of the law pass by congress, but a decision by the bureaucrats in charge of all the little details in carrying out the law.

Consider the Federal Communication Commission (FCC) regulation of the Internet. It bases its Continue reading

Instrumenting masscan for AFL fuzzing

This blog post is about work in progress. You probably don't want to read it.




So I saw this tweet today:




As it turns it, he's just fuzzing input files. This is good, he's apparently already found some bugs, but it's not a huge threat.

Instead, what really needs to be fuzzed is network input. This is chronic problem with AFL, which is designed for inserting files, not network traffic, into programs.

But making this work is actually pretty trivial. I just need to make a tiny change to masscan so that instead of opening a libpcap adapter, it instead opens a libpcap formatted file.

This change was trivial, successfully running it is tough. You have to configure the command-line so all IP addresses match up with the libpcap file content, which is a pain. I created a sample lipcap file and checked it into the project, along with a help document explaining it. Just git clone the project, run make, then run this command line to see it Continue reading

Micro-segmentation Defined – NSX Securing “Anywhere”

The landscape of the modern data center is rapidly evolving. The migration from physical to virtualized workloads, move towards software-defined data centers, advent of a multi-cloud landscape, proliferation of mobile devices accessing the corporate data center, and adoption of new architectural and deployment models such as microservices and containers has assured the only constant in modern data center evolution is the quest for higher levels of agility and service efficiency. This march forward is not without peril as security often ends up being an afterthought. The operational dexterity achieved through the ability to rapidly deploy new applications overtakes the ability of traditional networking and security controls to maintain an acceptable security posture for those application workloads. That is in addition to a fundamental problem of traditionally structured security not working adequately in more conventional and static data centers.

Without a flexible approach to risk management, which adapts to the onset of new technology paradigms, security silos using disparate approaches are created. These silos act as control islands, making it difficult to apply risk-focused predictability into your corporate security posture, causing unforeseen risks to be realized. These actualized risks cause an organization’s attack surface to grow as the adoption of new compute Continue reading

Technology Short Take #67

Welcome to Technology Short Take #67. Here’s hoping something I’ve collected for you here proves useful!

Networking

  • Anthony Burke has written a script that uses VMware NSX to protect VMware Log Insight instances. More information on the script is in his blog post.
  • Russ White tackles the issue of networking engineers needing to learn to code. Is it necessary? Russ thinks so—but probably not for the reasons you might think. I tend to agree with Russ’ line of thinking.
  • This article from Marcos Hernandez shows one way to do dynamic routing in OpenStack. It’s a bit of a hack, to be honest, but it gets the job done until dynamic routing makes its way into OpenStack Neutron (which looks like it may have landed in the Mitaka release—can anyone confirm?).
  • Jason Messer has an article describing how networking works with Windows containers.
  • Tom Hollingsworth discusses how the rise of overlay networks killed large layer 2 networks and tools for building large layer 2 networks, like TRILL.
  • Dmitri Kalintsev examines some options for addressing storage-related connectivity in NSX environments.

Servers/Hardware

My fellow Republicans: don’t support Trump

Scott Adams, the creator of the Dilbert comic strip, has a post claiming a Trump presidency wouldn't be as bad as people fear. It's a good post. But it's wrong.

Trump is certainly not as bad as his haters claim. Trump not only disables the critical-thinking ability of his supporters, but also of his enemies. In most conversations, I end up defending Trump -- not because I support him as a candidate, but because I support critical-thinking. He's only racist sometimes, most of the time I love his political incorrectness.

But with all that said, he would indeed be a horrible president. As a long-term Republican, I'd prefer a Hillary Clinton presidency, and I hate Hillary to the depths of my soul. She's corrupt, and worst of all, she's a leftist.

But there's a thing worse than being a leftist (or right-winger) and that's being a "populist demagogue". Populist demagogues tell you that all your problems are caused by them (you know, those people), and present unrealistic solutions to problems. They appeal to base emotion and ignorance.

When nations fail because of politics, it's almost always due to populist demagogues. Virtually all dictators are a "man of the people", protecting Continue reading

Drumpf: this is not how German works

In our willingness to believe any evil of Trump, some have claimed his original name was "Drumpf". This isn't true, this isn't how the German language works. Trump has the power to short-circuit critical thinking in both his supporters and his enemies. The "Drumpf" meme is just one example.

There was no official pronunciation or spelling of German words/names until after Trump's grandfather was born. As this The Guardian article describes, in the city ("Kallstadt") where Trump's grandfather was born, you'll see many different spellings of the family name in the church's records. like "Drumb, Tromb, Tromp, Trum, Trumpff, Dromb" and Trump. A person might spell their name different ways on different documents, and the names of children might be spelled different than their parent's. It makes German genealogy tough sometimes.

During that time, different areas of German had different dialects that were as far apart as Dutch and German are today. Indeed, these dialects persist. Germans who grow up outside of cities often learn their own local dialect and standard German as two different languages. Everyone understands standard German, but many villagers cannot speak it. They often live their entire lives within a hundred kilometers of where they grew Continue reading

From scratch: why these mass scans are important

The way the Internet works is that "packets" are sent to an "address". It's the same principle how we send envelopes through the mail. Just put an address on it, hand it to the nearest "router", and the packet will get forwarded hop-to-hop through the Internet in the direction of the destination.

What you see as the address at the top of your web browser, like "www.google.com" or "facebook.com" is not the actual address. Instead, the real address is a number. In much the same way a phonebook (or contact list) translates a person's name to their phone number, there is a similar system that translates Internet names to Internet addresses.

There are only 4 billion Internet addresses. It's a number between between 0 and 4,294,967,296. In binary, it's 32-bits in size, which comes out to that roughly 4 billion combinations.

For no good reason, early Internet pioneers split up that 32-bit number into four 8-bit numbers, which each has 256 combinations (256 × 256 × 256 × 256 = 4294967296). Thus, why write Internet address like "192.168.38.28" or "10.0.0.1". 

Yes, as you astutely point out, there are many more than 4 billion devices Continue reading

Doing a ‘full scan’ of the Internet right now

So I'm doing a "full" scan of the Internet, all TCP ports 0-65535 on all addresses. This explains the odd stuff you see from 209.126.230.7x.


I'm scanning at only 125kpps from 4 source IP addresses, or roughly 30kpps from each source address. This is so that I'll get below many thresholds for IDSs, which trigger when they see fast scans from a single address. The issue isn't to avoid detection, but to avoid generating work for people who get unnecessarily paranoid about the noise they see in their IDS logs.

This scan won't finish at this speed, of course, it won't get even close. Technically, it'd take 50 years to complete at this rate.

The point isn't create a comprehensive scan, but to do sampling scan. I'll let it run a week like this, which will get 0.1% of the Internet, and then stop the scan.

What am I looking for? I don't know. I'm just doing something weird in order to see what happens. With that said, I am testing any port I connect to with Heartbleed. This should give us an estimation of how many Internet-of-Things devices are still vulnerable to that bug. I'm Continue reading

Hiroshima is a complex memorial

In the news is Obama's visit to the Hiroshima atomic bomb memorial. The memorial is more complex than you think. It's not a simple condemnation of the bomb. Instead, it's a much more subtle presentation of the complexity of what happened.

I mention this because of articles like this one at Foreign Policy magazine, in which the author starts by claiming he frequently re-visits Hiroshima. He claims that the memorial has a clear meaning, a message, that he takes back from the site. It doesn't.

The museum puts the bombing into context. It shows how Japan had been in a constant state of war since the 1890s, with militaristic roots going back further in to Samurai culture. It showed how Japan would probably have continued their militaristic ways had the United States not demanded complete surrender, a near abdication of the emperor, and imposed a pacifist constitution on the country.

In other words, Japan accepts partial responsibility for having been bombed.

It doesn't shy away from the horror of the bomb. It makes it clear that such bombs should never again be used on humans. But even that has complexity. More people were killed in the Tokyo firebombing than Hiroshima Continue reading
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