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Is DefCon Wifi safe?

DEF CON is the largest U.S. hacker conference that takes place every summer in Las Vegas. It offers WiFi service. Is it safe?

Probably.

The trick is that you need to download the certificate from https://wifireg.defcon.org and import it into your computer. They have instructions for all your various operating systems. For macOS, it was as simple as downloading "dc25.mobileconfig" and importing it.

I haven't validated the DefCon team did the right thing for all platforms, but I know that safety is possible. If a hacker could easily hack into arbitrary WiFi, then equipment vendors would fix it. Corporations widely use WiFi -- they couldn't do this if it weren't safe.

The first step in safety is encryption, obviously. WPA does encryption well, you you are good there.

The second step is authentication -- proving that the access-point is who it says it is. Otherwise, somebody could setup their own access-point claiming to be "DefCon", and you'd happily connect to it. Encrypted connect to the evil access-point doesn't help you. This is what the certificate you download does -- you import it into your system, so that you'll trust only the "DefCon" access-point that has Continue reading

Slowloris all the things

At DEFCON, some researchers are going to announce a Slowloris-type exploit for SMB -- SMBloris. I thought I'd write up some comments.


The original Slowloris from several years creates a ton of connections to a web server, but only sends partial headers. The server allocates a large amount of memory to handle the requests, expecting to free that memory soon when the requests are completed. But the requests are never completed, so the memory remains tied up indefinitely. Moreover, this also consumes a lot of CPU resources -- every time Slowloris dribbles a few more bytes on the TCP connection is forces the CPU to walk through a lot of data structures to handle those bytes.

The thing about Slowloris is that it's not specific to HTTP. It's a principle that affects pretty much every service that listens on the Internet. For example, on Linux servers running NFS, you can exploit the RPC fragmentation feature in order to force the server to allocate all the memory in a box waiting for fragments that never arrive.

SMBloris does the same thing for SMB. It's an easy attack to carry out in general, the only question is how much resources are required Continue reading

Defending anti-netneutrality arguments

Last week, activists proclaimed a "NetNeutrality Day", trying to convince the FCC to regulate NetNeutrality. As a libertarian, I tweeted many reasons why NetNeutrality is stupid. NetNeutrality is exactly the sort of government regulation Libertarians hate most. Somebody tweeted the following challenge, which I thought I'd address here.


The links point to two separate cases.
  • the Comcast BitTorrent throttling case
  • a lawsuit against Time Warning for poor service
The tone of the tweet suggests that my anti-NetNeutrality stance cannot be defended in light of these cases. But of course this is wrong. The short answers are:

  • the Comcast BitTorrent throttling benefits customers
  • poor service has nothing to do with NetNeutrality

The long answers are below.

The Comcast BitTorrent Throttling

The presumption is that any sort of packet-filtering is automatically evil, and against the customer's interests. That's not true.

Take GoGoInflight's internet service for airplanes. They block access to video sites like NetFlix. That's because they often have as little as 1-mbps for the entire plane, which is enough to support many people checking email and browsing Continue reading

Transforming IT Security in Three Key Steps

Several years ago, the CEO of a Fortune 100 company remarked: “If you went to bed last night as an industrial company, you’re going to wake up this morning as a software and analytics company.”

Today, these words are more true than ever—but so is the reality that the digital transformation in business has also given rise to significant changes across the IT landscape and, in turn, significant new challenges for IT security.

As people, devices, and objects become more connected, protecting all these connections and environments has become a top priority for many IT organizations. At the same time, it’s also become one of their biggest challenges. Securing each and every interaction between users, applications, and data is no easy feat—especially when you consider that securing these interactions needs to be done across environments that are constantly changing and increasingly dynamic.

So how do you mitigate risk in a world where IT complexity and “anytime, anywhere” digital interactions are growing exponentially? For organizations that are embracing cloud and virtualized environments, three common-sense steps—enabled by a ubiquitous software layer across the application infrastructure and endpoints that exists independently of the underlying physical infrastructure—are proving to be key for providing Continue reading

Using Geolocation in Firepower Access Control Policies

The use of geolocation is fairly obvious in monitoring networks with Firepower Management Center. What may be less obvious is that Continents and Countries can also be specified as the source or destination of connections in an Access Control Policy. Basically, this geographical information becomes one more match criteria that can be used to identify traffic for a block or allow action.

To get to this capability, open the Access Control Policy that is in use by the Firepower device. Within the policy, open or create an applicable rule. On the network tab (where you configure the source and destination addresses) a Geolocation tab can also be found. Clicking on this tab exposes Continents and Countries. These can be added as sources and/or destinations.

ACPGEO

Note to reader: All Firepower content can be accessed by clicking here (or choosing Firepower from the menu at the top of the page).

As can be seen in the diagram above, I am creating a rule to block traffic to France. Before I save and deploy the policy changes to the device, I will confirm reachability to an IP address that exists in that part of Europe.

Last login: Mon Jul 17 11:48:29 on ttys000
PAULS:~ pauls$  Continue reading
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