Re: [OAUTH-WG] Mix-Up and CnP/ Code injection

Hi Nat,

wouldn't a maleware steal the response and the cookies from the device and replay it somewhere else. Or just steal the password? So no need to tweak the response?

best regards,
Torsten.

-------- Originalnachricht --------
Betreff: Re: [OAUTH-WG] Mix-Up and CnP/ Code injection
Von: Nat Sakimura <sakimura@gmail.com>
An: torsten@lodderstedt.net
Cc: jricher@mit.edu,oauth@ietf.org

>Hi Torsten,
>
>No, not defeating, but being able to find out if the input is tainted or
>not.
>
>Nat
>On Mon, May 9, 2016 at 07:46 <torsten@lodderstedt.net> wrote:
>
>> Are you suggesting OAuth should defeat maleware? So far, this was
>> considered to be handled by OS/Anti-Virus/other measures.
>>
>>
>> -------- Originalnachricht --------
>> Betreff: Re: [OAUTH-WG] Mix-Up and CnP/ Code injection
>> Von: Nat Sakimura <sakimura@gmail.com>
>> An: Torsten Lodderstedt <torsten@lodderstedt.net>
>> Cc: Justin Richer <jricher@mit.edu>,"<oauth@ietf.org>" <oauth@ietf.org>
>>
>> Yes, and unfortunately, that is a rather common attack these days.
>> Infesting a user device with a malware is probably easier than having the
>> client developer register its client to unknown server.
>>
>> 2016年5月1日(日) 16:54 Torsten Lodderstedt <torsten@lodderstedt.net>:
>>
>>> Hi Nat,
>>>
>>> please explain the attack. I assume the attacker would need to control
>>> network transmission or client device.
>>>
>>> kind regards,
>>> Torsten.
>>>
>>> Am 01.05.2016 um 07:36 schrieb Nat Sakimura <sakimura@gmail.com>:
>>>
>>> It actually depends on what risk level the transaction is at. For low
>>> risk transactions, just having separate redirection endpoint may be
>>> adequate. On the other hand, I can easily think of an attack that replaces
>>> iss on the authz response making the control invalid posing questions on
>>> whether it is worth introducing it.
>>> On Sun, May 1, 2016 at 14:21 Justin Richer <jricher@mit.edu> wrote:
>>>
>>>> I agree that we’re getting dangerously close to recommending signed
>>>> assertions at every step of the process, thereby bypassing HTTP. This was
>>>> the same mistake that WS-* and SOAP made, let’s not repeat it if we can.
>>>>
>>>>  — Justin
>>>>
>>>> On Apr 30, 2016, at 10:57 AM, Torsten Lodderstedt <
>>>> torsten@lodderstedt.net> wrote:
>>>>
>>>> Hi Nat,
>>>>
>>>> sure, one could also authenticate and cryptographically protect the
>>>> redirect response. Leveraging OIDC concepts is an idea worth considering
>>>> but they should be adopted to the OAuth philosophy. The id token as used in
>>>> the hybrid flows mixes an identity assertion with elements of transport
>>>> security measures. A OAuth AS does not provide identity data to clients, so
>>>> we only need the transport security part.
>>>>
>>>> I personally would prefer a OAuth response object (similar to request
>>>> object you have proposed) over the id token. Such a response object could
>>>> contain (and directly protect) state, code and other response values. I
>>>> consider this the more elegant design and it is easier to implement then
>>>> having detached signatures over hash values of codes or access tokens.
>>>> Moreover, it would allow to encrypt the response as well.
>>>>
>>>> Generally, our threat analysis so far does not have provided
>>>> justification for cryptographically protected redirect responses. All
>>>> proposals currently on the table stop mix up and code injection using
>>>> simpler mechanisms.
>>>>
>>>> I think OAuth 2.0 is a huge success due to its balance of versatility,
>>>> security and _simplicity_. We definitely need to keep it secure, but we
>>>> should also keep it as simple as possible.
>>>>
>>>> kind regards,
>>>> Torsten.
>>>> Am 29.04.2016 um 10:08 schrieb Nat Sakimura:
>>>>
>>>> As I look at it more and more, it started to look like the problem of
>>>> accepting tainted values without message authentication. To fix the root
>>>> cause, we would have to authenticate response. ID Token was designed to
>>>> also serve as a solution anticipating it.
>>>>
>>>> Any concrete ideas?
>>>>
>>>> On Sat, Apr 23, 2016 at 04:47 Torsten Lodderstedt <
>>>> torsten@lodderstedt.net> wrote:
>>>>
>>>>> Hi all,
>>>>>
>>>>> discussion about Mix-Up and CnP seems to have stopped after the session
>>>>> in BA - at least in the OAuth WG. There is a discussion about
>>>>> mitigations in OpenId Connect going on at the OpenId Connect mailing
>>>>> list.
>>>>>
>>>>> I'm very much interested to find a solution within the OAuth realm as
>>>>> I'm not interested to either implement two solutions (for OpenId Connect
>>>>> and OAuth) or adopt a OpenId-specific solution to OAuth (use id! tokens
>>>>> in the front channel). I therefore would like to see progress and
>>>>> propose to continue the discussion regarding mitigations for both
>>>>> threats.
>>>>>
>>>>> https://tools.ietf.org/html/draft-ietf-oauth-mix-up-mitigation-00
>>>>> proposes reasonable mitigations for both attacks. There are alternatives
>>>>> as well:
>>>>> - mix up:
>>>>> -- AS specific redirect uris
>>>>> -- Meta data/turi
>>>>> (https://tools.ietf.org/html/draft-sakimura-oauth-meta-07#section-5)
>>>>> - CnP:
>>>>> -- use of the nonce parameter (as a distinct mitigation beside state for
>>>>> counter XSRF)
>>>>>
>>>>> Anyone having an opinion?
>>>>>
>>>>> best regards,
>>>>> Torsten.
>>>>>
>>>>> _______________________________________________
>>>>> OAuth mailing list
>>>>> OAuth@ietf.org
>>>>> https://www.ietf.org/mailman/listinfo/oauth
>>>>>
>>>>
>>>> _______________________________________________
>>>> OAuth mailing list
>>>> OAuth@ietf.org
>>>> https://www.ietf.org/mailman/listinfo/oauth
>>>>
>>>>
>>>> --
>> Nat Sakimura
>> Chairman of the Board, OpenID Foundation
>> Trustee, Kantara Initiative
>>
>-- 
>Nat Sakimura
>Chairman of the Board, OpenID Foundation
>Trustee, Kantara Initiative