
76 Popular Apps Confirmed Vulnerable to Interception of TLS-Protected Data - clairity
https://medium.com/@chronic_9612/76-popular-apps-confirmed-vulnerable-to-silent-interception-of-tls-protected-data-2c9a2409dd1
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pmontra
Very interesting. I always felt that I better do mobile banking on a 3G/4G
connection than over WiFi, so I'm already performing the mitigation action
even if I'm not using any of those apps. I'm also on the other mobile OS but I
think this could be a more general problem.

Unfortunately the post falls short of giving any advice to developers. They
are the ones who made the mistakes and should fix them.

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spaceboy
If it's "TLS-Protected data" then how can it be intercepted? I thought the
idea behind TLS is to protect data on the wire. The only way I can think TLS
would be intercepted is if a rogue certificate was placed somewhere

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tialaramex
Mathematics lets us solve most of the problems of how to communicate securely
at a distance, but one it can't tackle. Who are we communicating with? In TLS
this problem is left to one or more trusted third parties, the Certificate
Authorities. But, which CAs should we trust?

Developers of an application using TLS have to make this choice, but they may
not do a very good job. Worse, they may not even realise they were supposed to
make a choice at all. For Safari the decisions are being made by some bunch of
Apple engineers who hopefully know a lot about TLS and trust. For Firefox, the
decisions are made in public, anyone can help Mozilla make policy, both
experts and amateurs are welcome to bring their insight. But for some random
iOS app, the decision was probably made by some guy with no specialist
knowledge, copy-pasting examples they found with Google.

Now, if they pick "Only trust Symantec's public CA" and six months later their
company tries to switch from Symantec to Comodo, they'll soon realise their
goof. It may cost them a lot of money, but no real harm was done.

But what if they pick "Just trust anybody"? Well, everything _seems_ fine. It
all works, the data is encrypted, there's no outward sign that anything is
wrong. Until a bad guy makes their own CA (takes about five minutes) and
issues whatever TLS certificates they want, which the app will accept happily
and talk to the bad guy instead if they're able to intercept the network
connection.

