0

Discard Routing for RFC1918 Addresses

While working with firewalls for the last few years, I’ve seen many logs polluted with scanning traffic. Obviously this is the type of thing that I want to see when someone is legitimately scanning, or attempting to scan, through the firewall. However, there are a few cases that seeing this traffic is simply an indication of some other issue in the network.

An example I have seen on several occasions is someone configuring a network management station to discover 192.168.0.0/16, 172.16.0.0/12 or 10.0.0.0/8. If not properly handled in the routed network architecture, the associated traffic could make its way to the firewall or even to the ISP. An ASA might block the traffic due to policy, reroute it back toward the internal network, drop it due to the intra-interface hairpin configuration, or forward it onward. In most cases, this traffic will cause a lot of “noise” in the syslogs produced by the firewall.

To fully understand the problem, the diagram below can be used for discussion–

In this example, R1 has a static default route that points to the IP address of FW1. R1 advertises this via EIGRP to its internal neighbors. If a networked host attempts to reach Continue reading

0

Extracting the SuperFish certificate

I extracted the certificate from the SuperFish adware and cracked the password ("komodia") that encrypted it. I discuss how down below. The consequence is that I can intercept the encrypted communications of SuperFish's victims (people with Lenovo laptops) while hanging out near them at a cafe wifi hotspot. Note: this is probably trafficking in illegal access devices under the proposed revisions to the CFAA, so get it now before they change the law.

procdump -ma VisualDiscovery.exe super.dmp

0

Some notes on SuperFish

What's the big deal?

0

How to add Cisco ASA 8.4(2) or ASA 9.1(5) to GNS3 1.2.x and get it working ?

GNS3 team has done a great job in stabilizing the ASA implementation. On the new version1.2.x they have already set all default options

0

Securing BFD now possible!

Confession Time.

I am guilty of committing several sins. One that egregiously stands out is writing two IETF specs for BFD security (here and here) without considering the impact on the routers and switches implementing those specs. Bear in mind that Bi-directional Forwarding Detection (BFD) is a hard protocol to implement well. Its hard to get into a conversation with engineers working on BFD without a few of them shedding copious quantities of tears on what it took them to avoid those dreaded BFD flaps in scaled setups. They will tell you how they resorted to clever tricks (hacks, if you will) to process BFD packets as fast as they could (plucking them out of order from a shared queue, dedicated tasks picking up BFD packets in the ISR contexts, etc) . In a candid conversation, an ex-employee of a reputed vendor revealed how they stage managed their BFD during a demo to a major customer since they didnt want their BFD to flap while the show (completely scripted) was on. So, long story short — BFD is hard when you start scaling. It just becomes a LOT worse, when you add security on top of it.

The reason BFD is hard is because of Continue reading

0

Securing BFD now possible!

Confession Time.

I am guilty of committing several sins. One that egregiously stands out is writing two IETF specs for BFD security (here and here) without considering the impact on the routers and switches implementing those specs. Bear in mind that Bi-directional Forwarding Detection (BFD) is a hard protocol to implement well. Its hard to get into a conversation with engineers working on BFD without a few of them shedding copious quantities of tears on what it took them to avoid those dreaded BFD flaps in scaled setups. They will tell you how they resorted to clever tricks (hacks, if you will) to process BFD packets as fast as they could (plucking them out of order from a shared queue, dedicated tasks picking up BFD packets in the ISR contexts, etc) . In a candid conversation, an ex-employee of a reputed vendor revealed how they stage managed their BFD during a demo to a major customer since they didnt want their BFD to flap while the show (completely scripted) was on. So, long story short — BFD is hard when you start scaling. It just becomes a LOT worse, when you add security on top of it.

The reason BFD is hard is because of Continue reading

0

Technical terms are not ambiguous

I see technical terms like "interference" and "authorization" in laws. As a technical person, this confuses me. I have a different understand of these terms than how the courts might interpret them. Courts insist that these words must be interpreted using their common everyday meanings, not their technical meanings. Yet, situations are inherently technical, so the common meanings are ambiguous.


Take for example the law that forbids causing radio interference:

No person shall willfully or maliciously interfere with or cause interference to any radio communications of any station licensed or authorized by or under this chapter or operated by the United States Government.

Interference seems like a common, non-technical term, but it's unlikely that's the meaning here. Interference has a very technical meaning, as demonstrated by this long Wikipedia article on "radio interference". There are entire books dedicated this this subject. It's a big technical deal, it's unreasonable to think the law means anythings else.

This is important when looking at the recent "Marriott WiFi Jamming" case, because Marriott did not cause "radio interference" or "jamming". Instead, what they did was send "deauth" packets. Using a real world analogy, jamming is like a locked door, blocking access against Continue reading

0

No, you can’t make things impossible to reverse-engineer

I keep seeing this Wired article about somebody announcing a trick to make software "nearly impossible" to reverse-engineer. It's hype. The technique's features are no better at stopping reverse-engineering than many existing techniques, but has an enormous cost on the system that makes it a lot worse.

We already have deterrents to reverse-engineering. Take Apple iTunes, for example, which has successfully resisted reverse-engineering for years. I think the last upgrade to patch reverse-engineered details was in 2006. Its anti-reverse-engineering techniques aren't wonderful, but are instead simply "good enough". It does dynamic code generation, so I can't easily reverse engineer the static code in IDApro. It does anti-debugging tricks, so I can't attach a debugger to the running software. I'm sure if I spent more time at it, I could defeat these mechanisms, but I'm just a casual reverse-engineer who is unwilling to put in the time.

The technique described by Wired requires that the software install itself as a "hypervisor", virtualizing parts of the system. This is bad. This is unacceptable for most commercial software, like iTunes, because it would break a lot of computers. It might be acceptable for really high-end software that costs more than the computer, in Continue reading

0

8 Networking Trends to Watch in 2015

by Kevin Dooley originally published on the Auvik blog Let’s lay it on the table: I’m really bad at predicting long-term

0

Explaining the Game of Sony Attribation

Attribution is a blame game. It’s not about who did it, but who is best to blame. Ambulance chasing lawyers sue whoever has the most money, not who is most responsible. I point this out because while the U.S. “attributes” the Sony hack to North Korea, this doesn’t mean North Korea did the attack. Instead, it means that North Korea was involved enough to justify sanctions. It still leaves the question of “who did it” unresolved.

The situation is comparable to the recent terrorist attack on Charlie Hebdo in France. Two brothers committed the crime, but “Al Qaeda of the Arabian Peninsula” (AQAP) claims credit. The precise facts are murky, but we have a good idea what happened. While AQAP probably provided some training, it appears the attack was conceived, planned, financed, and executed by the two brothers themselves without AQAP help. The brothers took out bank loans and purchased the weapons from the criminal (not terrorist) underground. They appear to have planned the attacks with a friend from ISIS (the Islamic “Caliphate”), an organization hostile to AQAP. It appears most of their training was in France rather than during their trip to AQAP camps in Yemen. AQAP waited Continue reading

0

A lesson in the corrupt press

In the last few days, both President Obama and Republican presidential candidate Chris Christie made similar statements about vaccination. They both said that parents should absolutely vaccinate their children, but that it's still ultimately the parent's choice (and not government's). While the statements were similar, the press reported these stories completely differently. They praised Obama for calling for vaccination, and lambasted Christie for siding with anti-vaxxers on parental choice.

0

Securing Your Connection Anywhere You Go

We all know that there are a lot of incomplete security models. Firesheep made this fact painfully obvious to those who regularly work from public hotspots. Although this issue extends beyond insecure wireless deployments, unencrypted hotspots are an easy target. When network traffic isn’t secured in the application layers AND that same traffic is not secured in the network or datalink layers, bad things can and do happen.

TLDR–This article solves this problem by utilizing a Meraki MX60 and the VPN client Native on OSX. To skip to the good stuff, click here.

One approach that some people decide to employ is utilizing a VPN connection for their Internet traffic when connected to untrusted networks. For years, enterprises have utilized these controls to allow secure access to corporate resources. A common trend to day includes utilizing “the cloud” for sensitive enterprise and personal data. While these systems *should* be appropriate resilient, we know that is not always the case. In addition to that, federated authentication schemes and password reuse can also pose additional risk to broken systems and less security conscious users.

Having easy access to some gear, I have been using a Meraki MX60 for a few months. This device makes the configuration Continue reading

0

The Vast World of Fraudulent Routing

As network security engineers have attempted to categorize blocks of IP addresses associated with spam or malware for subsequent filtering at their firewalls, the bad guys have had to evolve to continue to target their victims.  Since routing on the global Internet is based entirely on trust, it’s relatively easy to commandeer IP address space that belongs to someone else.  In other words, if the bad guys’ IP space is blocked, well then they can just steal someone else’s and continue on as before.

In an attempt to cover their tracks, these criminals will sometimes originate routes using autonomous system numbers (ASNs) that they don’t own either.  In one of the cases described below, perpetrators hijacked the victim’s ASN to originate IP address space that could have plausibly been originated by the victim.  However, in this case, the traffic was misdirected to the bad guy and an unsophisticated routing analysis would have probably shown nothing amiss.

The weakness of all spoofing techniques is that, at some point, the routes cross over from the fabricated to the legitimate Internet — and, when they do, they appear quite anomalous when compared against historical data and derived business Continue reading

0

Nobody thought BlackPhone was secure — just securer

An exploitable bug was found in BlackPhone, a "secure" Android phone. This is wildly misinterpreted. BlackPhone isn't a totally secure phone, such a thing is impossible. Instead, it's a simply a more secure phone. I mention this because journalists can't tell the difference.

0

Some notes on GHOST

I haven't seen anybody compile a list of key points about the GHOST bug, so I thought I'd write up some things. I get this from reading the code, but mostly from the advisory.

Most things aren't vulnerable. Modern software uses getaddrinfo() instead. Software that uses gethostbyname() often does so in a way that can't be exploited, such as checking inet_addr() first. Therefore, even though software uses the vulnerable function doesn't mean it's actually vulnerable.

Most vulnerable things aren't exploitable. This bug is hard to exploit, only overwriting a few bytes. Most of the time, hackers will only be able to crash a program, not gain code execution.

Many exploits are local-only. It needs a domain-name of a thousand zeroes. The advisory identified many SUID programs (which give root when exploited) that accept such names on the command-line. However, it's really hard to generate such names remotely, especially for servers.

Is this another Heartbleed? Maybe, but even Heartbleed wasn't a Heartbleed. This class of bugs (Heartbleed, Shellshock, Ghost) are hard to exploit. The reason we care is because they are pervasive, in old software often going back for more than a decade, in components used by other software, and Continue reading

0

You shouldn’t be using gethostbyname() anyway

Today's GHOST vulnerability is in gethostbyname(), a Sockets API function from the early 1980s. That function has been obsolete for a decade. What you should be using is getaddrinfo() instead, a newer function that can also handle IPv6.

The great thing about getaddrinfo() is the fact that it allows writing code that is agnostic to the IP version. You can see an example of this in my heartleech.c program.

x = getaddrinfo(hostname, port, 0, &addr);
fd = socket(addr->ai_family, SOCK_STREAM, 0);
x = connect(fd, addr->ai_addr, (int)addr->ai_addrlen);

What you see here is your normal call to socket() and connect() just use the address family returned by getaddrinfo(). It doesn't care if that is IPv4, IPv6, or IPv7.

The function actually returns a list of addresses, which may contain a mixture of IPv4 and IPv6 addresses. An example is when you lookup www.google.com:

[ ] resolving "www.google.com"
[+]  74.125.196.105:443
[+]  74.125.196.147:443
[+]  74.125.196.99:443
[+]  74.125.196.104:443
[+]  74.125.196.106:443
[+]  74.125.196.103:443
[+]  [2607:f8b0:4002:801::1014]:443

My sample code just chooses the first one in the list, Continue reading

0

Using GNS3 for Basic Network Security Testing

(The original idea for this post came from a post my blog, “The Console Port,” which you can find at

0

Needs more Hitler

Godwin's law applies especially to inappropriate, inordinate, or hyperbolic comparisons with Nazis. The law would not apply to mainstays of Nazi Germany such as genocide, eugenics, racial superiority, or to a discussion of other totalitarian regimes, if that was the explicit topic of conversation, because a Nazi comparison in those circumstances may be appropriate.

Last week, I wrote a piece about how President Obama's proposed cyber laws were creating a Cyber Police State. The explicit topic of my conversation is totalitarian regimes.

This week, during the State of the Union address, I compared the text of Mein Kampf to the text of President Obama's speech. Specifically, Mein Kampf said this:

The state must declare the child to be the most precious treasure of the people. As long as the government is perceived as working for the benefit of the children, the people will happily endure almost any curtailment of liberty and almost any deprivation.

Obama's speech in support of his cyber legislation says this:

No foreign nation, no hacker, should be able to shut down our networks, steal our trade secrets, or Continue reading

0

Drums of cyberwar: North Korea’s cyber-WMDs

People ask me if today's NYTimes story changes my opinion that North Korea didn't do the Sony hack. Of course it doesn't. Any rational person can tell that the story is bogus. Indeed, such stories hint the government is hiding something.

The story claims the NSA has thoroughly hacked North Korea since 2010, and that's what enabled the US government to tell who was responsible for the Sony hack. But if this were true, then we hacked first, and the Sony hack is retaliation -- meaning we had no justification for Obama's sanctions. But, if the story is false, then again sanctions against North Korea aren't justified, because we don't have the proof our government claims. True or false, this story means the U.S. sanctions against North Korea aren't justified.

The reason this story is nonsense is that it's not journalism. It relies almost entirely on anonymous sources in the government. These aren't anonymous whistle-blowers who fear retaliation, but government propagandists who don't want to be held accountable. The government exploits the New York Times, promising them exclusive breaking news in exchange for them publishing propaganda. This allows government to have a story that is simultaneous true and false, Continue reading

0

Notes on the CIA spying case

The CIA announced it wasn't going to punish those responsible for spying/hacking on Senate computers. Since journalists widely get this story wrong, I thought I'd write up some notes getting it right. That's because while the CIA organization is guilty of gross misconduct, it's actually likely that no individual employees did anything wrong. The organization is guilty, but (possibly) the people aren't.

The first thing to note is that no hacking happened. These were CIA computers, at a CIA facility, managed by CIA sysadmins, who had the admin passwords.

That's the complicated bit. In 2009 when the Intelligence committee demanded to look at the torture/interrogation documents, the CIA balked about the security issues of staffers taking documents offsite. Therefore, they came to an agreement with the Senate: the CIA would set up a special secured network at their building, disconnected from the rest of the CIA network. The Senate staffers would go there to work. Documents would be transferred from the CIA's main network onto this special network by hand (probably USB flash drive or something).

The Senate committee didn't have to agree to this. By law, they have oversight, and can make decisions that screw the CIA. But the Continue reading