Wednesday, October 22, 2014

Man in the Middle

Excerpt from: http://iamsteve.in/08/2013/what-are-man-in-the-middle-attacks-arp-spoofing/

If we ever share a WiFi network, chances are I can intercept what you’re doing.

‘Man in the middle’ attacks have been around for about as long as the Internet itself, and so those familiar with network security will already be well aware of the threat posed by ‘ARP spoofing’ or ‘poisoning’. The thing is, most people aren’t familiar with the basics of protecting their communications online, and even those who are don’t always take the precautions that they know in theory they should be.



Wifi Pineapple What is a ‘man in the middle’ attack?

Without going into the technical details of how these attacks actually work, a ‘man in the middle’ attack essentially stick their hand up first when your device is looking for an appropriate router to connect to, and pretends to be where you actually want to gain access to.
Essentially, instead of connecting to the network through the route you might expect (like a wireless router) you get redirected via another device first. This means that all of your traffic is flowing through an additional step before getting onto the Internet, and allows anybody in control of that piece of equipment access to it.

This is incredibly easy to do, there are many real world examples of this in the field. One of the more infamous comes in the decidedly fruity shape of the ‘WiFi’ pineapple… a rogue device that convinces network traffic to connect to it rather than the intended, legitimate source. However, even this is bulky in comparison to the possibilities that are now on offer through mobile phone apps… which are harder to find or identify if they are ever detected.
What are the dangers?

It should hopefully be pretty obvious why you wouldn’t want wee Davey sitting in the corner of Starbucks intercepting everything that you’re doing online, but even if you’re not all that concerned about anybody knowing which websites you visit and when, there are other, more potent dangers that the man in the middle poses.

Whilst SSL is widely used for financial transactions (such as over PayPal), in practice, it’s far from perfect. Many websites still do not offer SSL connections by default, requiring you instead to specifically turn them on. Many simply require encryption for the login process, and not anything afterwards (which we’ll get to in the next section). Even those that do default to a secure connection, often still run the insecure service as well. It wasn’t too long ago that Facebook were operating precisely in this fashion.

Since most people take this for granted, it is fairly easy to redirect a computer under the spell of this sort of poisoning attack to the non-SSL version of a website, without it ever occurring to the user to check.

How can I protect myself?
Without a doubt, these attacks are something that everybody should be aware of, but most people aren’t – partly because of the technical nature of the problem. However, there are some simple things you can do to avoid this type of attack.

HTTPS Everywhere
HTTPS Everywhere is a plugin for Google Chrome and Firefox which automatically forces the browsers to go to the secure version of a website where available, and send all of the traffic over SSL. No need to fiddle about with the settings of individual settings on different services, or working out where offers SSL and where doesn’t. HTTPSEverywhere does the work for you.

Further Securing against the man in the middle
Using an encryption services will keep the data you transmit over a network secure, which is the primary concern of man in the middle attacks. However, they won’t necessarily stop the denial of service attack that was explained above. Whilst there isn’t many, there are a few utilities that Android, Windows, and Mac users can make use of to kill off an attempt completely, or at least be notified of it happening. If anybody is aware of any other effective utilities – especially for Windows/the iPhone – please get in touch!

Be vigilant
There is no single way to completely prevent man in the middle attacks from impacting your network connectivity. Most of the advice that is given from people who skim the surface of this topic boils down to “don’t use open wireless networks”. Uhh, right. Nice idea pal, but not a practical reality. As we rely more and more on disparate WiFi networks, we all need to be aware of the dangers of insecure communications, and take steps to reduce the risks. These aren’t limited solely to open networks, but any that are shared – such as in a workplace or University. Just because they are secured with a keyphrase, doesn’t mean they are any more secure than a public hotspot in an Internet cafe. Some types of wireless network are more secure than others, but it’s up to you to ensure the integrity of your own data.

If you only do one thing after reading this blog, then sign up for a VPN service and start using it on shared networks. Make sure you check that you’re connected to websites in SSL when you expect to be, and if something doesn’t seem right, disconnect and login somewhere else. It’s a first step towards keeping your personal information safe.

See more at http://iamsteve.in/08/2013/what-are-man-in-the-middle-attacks-arp-spoofing/

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