[cryptography] yet another certificate MITM attack

Jeffrey Walton noloader at gmail.com
Fri Jan 11 11:16:19 EST 2013


On Fri, Jan 11, 2013 at 10:04 AM, Jeffrey Walton <noloader at gmail.com> wrote:
> On Thu, Jan 10, 2013 at 7:47 PM, Peter Gutmann
> <pgut001 at cs.auckland.ac.nz> wrote:
>> Jon Callas <jon at callas.org> writes:
>>
>>>Others have said pretty much the same in this thread; this isn't an MITM
>>>attack, it's a proxy browsing service.
>>
>> Exactly.  Cellular providers have been doing this for ages, it's hardly news.
>>
>> (Well, OK, given how surprised people seem to be, perhaps it should be news in
>> order to make it more widely known :-).
> Its not so much surprise as it is frustration (for me).
>
> My secure coding guides include something similar to:
>   * Do not send sensitive information, such as usernames
>     and passwords, through query parameters (GET)
>   * Use HTTPS, send using POST
>
> How do web applications pin their certificates when the language
> (HTML) and the platform (Browser) do not offer the functionality?
>
> How do the proxies determine which HTTPS traffic is benign, "public
> information" vs sensitive, "private information"?
>
> How do carriers know when its OK to log benign, "public information"
> vs sensitive, "private information"?
>
> How do carriers differentiate the benign, "public information" data
> from the sensitive, "private information" before selling it to firms
> like GIGYA?
>
> How do we teach developers to differentiate between the good
> "men-in-the-middle" vs the bad "man-in-the-middle"?
>
> Until we can clearly answer those questions, I will call a pot and
> kettle black. Interception is interception, and its Man-in-the-Middle.
> Period.
>
> From my [uneducated] data security point of view, it is best to stop
> the practices. HTTPS is the cue to stop the standard operating
> procedures on consumer information because the information is (or
> could be) sensitive. All I care about is the user and the data (as a
> person who endures life after a data breach).

This came on off-list:

> IMNSHO, if Nokia didn't inform their customers that they were doing
> this--especially for HTTPS traffic--in their TOS, then it might as well be a
> MITM. At least in the US, people still have a reasonable expectation of
> privacy (in a legal sense at least).
There are at least two endpoints in a secure channel. Did they inform
the other endpoint, too?

Perhaps they should be using the evil bit in the TCP/IP header to
indicate someone (or entity) is tampering with the secure channel?
https://tools.ietf.org/html/rfc3514.

Jeff



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