A Geek With Guns

Chronicling the depravities of the State.

Another Bang Up Job

with 2 comments

Legacy cellular protocols contained numerous gaping security holes, which is why attention was paid to security when Long-Term Evolution (LTE) was being designed. Unfortunately, one can pay attention to something and still ignore it or fuck it up:

The attacks work because of weaknesses built into the LTE standard itself. The most crucial weakness is a form of encryption that doesn’t protect the integrity of the data. The lack of data authentication makes it possible for an attacker to surreptitiously manipulate the IP addresses within an encrypted packet. Dubbed aLTEr, the researchers’ attack causes mobile devices to use a malicious domain name system server that, in turn, redirects the user to a malicious server masquerading as Hotmail. The other two weaknesses involve the way LTE maps users across a cellular network and leaks sensitive information about the data passing between base stations and end users.

Encrypting data is only one part of the puzzle. Once data is encrypted the integrity of the data must be protected as well. This is because encrypted data looks like gibberish until it is decrypted. The only way to know whether the encrypted data you’ve received hasn’t been tampered with is if some kind of cryptographic integrity verification has been implemented and used.

How can you protect yourself form this kind of attack? Using a Virtual Private Network (VPN) tunnel is probably your best bet. The OpenVPN protocol is used by numerous VPN providers that provide clients for both iOS and Android (as well as other major operating systems such as Windows, Linux, and macOS). OpenVPN, unlike LTE, verifies the integrity of encrypted data and rejects any data that appears to have been tampered with. While using a VPN tunnel may not prevent a malicious attacker from redirecting your LTE traffic, it will ensure that the attacker can’t see your data as a malicious VPN tunnel will fail to provide data that passes your client’s integrity checker and thus your client will cease receiving or transmitting data.

Written by Christopher Burg

July 3rd, 2018 at 11:00 am

2 Responses to 'Another Bang Up Job'

Subscribe to comments with RSS or TrackBack to 'Another Bang Up Job'.

  1. Not seen in the wild, but the requirement for a custom software-defined radio running LTE (hacked version) doesn’t seem like the high bar they are making it out to be.

    The cheapest SDR I’ve seen is just over 100 bucks, and the best is about 5 grand.

    Might not be the kid camped out at Starbucks, but I bet the FBI/CIA/EIEIO have a setup soon enough.

    Zendo Deb

    3 Jul 18 at 20:03

  2. Yeah, software defined radios aren’t terribly expensive today and the price continues to drop. Even a high end SDR will probably cost a few hundreds bucks in a couple of years.

    Christopher Burg

    9 Jul 18 at 07:34

Leave a Reply