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 <[email protected]>: > 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 <[email protected]>: > > 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 <[email protected]> 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 < >> [email protected]> 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 < >> [email protected]> 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 >>> [email protected] >>> https://www.ietf.org/mailman/listinfo/oauth >>> >> >> _______________________________________________ >> OAuth mailing list >> [email protected] >> https://www.ietf.org/mailman/listinfo/oauth >> >> >> -- Nat Sakimura Chairman of the Board, OpenID Foundation Trustee, Kantara Initiative
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