Facebook is, in this case, the service provider: it has your login data and your pictures. The app is the consumer, and as the user, you want to use the app to do something with your pictures. You specifically gave this app access to your pictures, which OAuth is managing in the background.
Your smart home devices — toaster, thermostat, security system, etc. These devices use what OAuth calls confidential authorization. OAuth is about authorization and not authentication. Authorization is asking for permission to do stuff.
Authentication is about proving you are the correct person because you know things. An OAuth token is like that valet key. You can give each consumer a different valet key. They never have the full key or any of the private data that gives them access to the full key. There are 3 main players in an OAuth transaction: the user, the consumer, and the service provider. So, how do you solve this?
This can be solved by using the authorization code flow and only accepting tokens directly from the authorization server's token endpoint, and by using a state value that is unguessable by an attacker.
Since the OAuth specification does not specify how to perform user-agent redirection for mobile applications, it may seem natural to use a mobile browser or an embedded browser i. Again, an issue that is highlighted in the research paper by CMU is as under:. The WebView usage is very common for service providers that utilize a single protocol flow for both web and mobile relying parties. Unlike Facebook and Google, these service providers do not facilitate OAuth flows for mobile relying party using their own mobile applications.
Instead, they choose to use their websites to conduct all mobile OAuth transactions. This is a common misconception, as we have not found a single case in our study where a mobile browser or WebView is used securely for OAuth. Everything is moving to social and mobile, integrations with Facebook and similar social websites. With the growing usage of smartphones, both businesses and users want quick access to services and systems.
OAUth is a great way to achieve that but like we mentioned above, it is essential to implement this in the right way else it can end up being a pain for your business and users. We are just a month away from the implementation of Europe's new privacy rule that is reshaping the internet. The importance of checksum is often ignored by many businesses until one day it strikes which is not often that As more and more businesses embrace the digital age, there is a need for continuous improvement in Information Appknox is the worlds most powerful plug and play security platform which helps Developers, Security Researchers and Enterprises to build a safe and secure mobile ecosystem using a system plus human approach to outsmart smartest hackers.
What is OAuth? Then what exactly is OAuth? Authentication Vs Authorization The OAuth website gives a simple metaphor to understand this - chocolate vs. OAuth for Mobile Applications Just like their web counterparts, mobile applications also need authentication and authorization. So, what's the big deal you ask? Understanding OAuth 1.
Published on Feb 12, Written by Harshit Agarwal. Harshit Agarwal is co-founder and CEO of Appknox, a mobile security suite that helps Enterprises and Financial institutions to automate mobile security. Author Website. Similar Blogs Apr 19, By this stage, you should have a relatively good understanding of which parts of the URI you can tamper with. The key now is to use this knowledge to try and access a wider attack surface within the client application itself.
Try to find ways that you can successfully access different subdomains or paths. However, you may be able to use directory traversal tricks to supply any arbitrary path on the domain.
Something like this:. Once you identify which other pages you are able to set as the redirect URI, you should audit them for additional vulnerabilities that you can potentially use to leak the code or token. For the authorization code flow , you need to find a vulnerability that gives you access to the query parameters, whereas for the implicit grant type , you need to extract the URL fragment.
One of the most useful vulnerabilities for this purpose is an open redirect. You can use this as a proxy to forward victims, along with their code or token, to an attacker-controlled domain where you can host any malicious script you like.
Note that for the implicit grant type, stealing an access token doesn't just enable you to log in to the victim's account on the client application. As the entire implicit flow takes place via the browser, you can also use the token to make your own API calls to the OAuth service's resource server. This may enable you to fetch sensitive user data that you cannot normally access from the client application's web UI. In addition to open redirects, you should look for any other vulnerabilities that allow you to extract the code or token and send it to an external domain.
Some good examples include:. In any OAuth flow, the user must approve the requested access based on the scope defined in the authorization request. The resulting token allows the client application to access only the scope that was approved by the user. But in some cases, it may be possible for an attacker to "upgrade" an access token either stolen or obtained using a malicious client application with extra permissions due to flawed validation by the OAuth service.
The process for doing this depends on the grant type. With the authorization code grant type , the user's data is requested and sent via secure server-to-server communication, which a third-party attacker is typically not able to manipulate directly.
However, it may still be possible to achieve the same result by registering their own client application with the OAuth service. For example, let's say the attacker's malicious client application initially requested access to the user's email address using the openid email scope. After the user approves this request, the malicious client application receives an authorization code.
If the server does not validate this against the scope from the initial authorization request, it will sometimes generate an access token using the new scope and send this to the attacker's client application:. The attacker can then use their application to make the necessary API calls to access the user's profile data. For the implicit grant type , the access token is sent via the browser, which means an attacker can steal tokens associated with innocent client applications and use them directly.
Ideally, the OAuth service should validate this scope value against the one that was used when generating the token, but this isn't always the case. As long as the adjusted permissions don't exceed the level of access previously granted to this client application, the attacker can potentially access additional data without requiring further approval from the user. When authenticating users via OAuth, the client application makes the implicit assumption that the information stored by the OAuth provider is correct.
This can be a dangerous assumption to make. Some websites that provide an OAuth service allow users to register an account without verifying all of their details, including their email address in some cases. An attacker can exploit this by registering an account with the OAuth provider using the same details as a target user, such as a known email address. Client applications may then allow the attacker to sign in as the victim via this fraudulent account with the OAuth provider.
When used for authentication, OAuth is often extended with an OpenID Connect layer, which provides some additional features related to identifying and authenticating users. For a detailed description of these features, and some more labs related to vulnerabilities that they can introduce, see our OpenID Connect topic. For developers, we've provided some guidance on how you can avoid introducing these vulnerabilities into your own websites and applications.
How to prevent OAuth authentication vulnerabilities. Add a comment. Active Oldest Votes. I'm going to go with 'You didn't understand it. Improve this answer. Community Bot 1 1 1 silver badge. Bob Aman Bob Aman 32k 9 9 gold badges 67 67 silver badges 95 95 bronze badges. I expected OAuth to be better, but it doesn't address or try to solve, current web "security considerations". I expect it to be complex security system that addresses problems of server authenticity, spoofing, but it's not and all common web security problems, but it's not.
Magic bullets don't exist. There is no such thing as perfect security, and using using OAuth certainly won't make something be secure. What it does do, is eliminate the need for a specific insecure anti-pattern, namely exposing username and password to third parties as a form of authorization grant. Criticizing the specification for failing to achieve something it wasn't trying to achieve and couldn't possibly achieve, even if it was trying is a little strange.
I think the OP was saying you could open a popup with a fake login panel and steal someone's password that way. A kind of phishing attack, I guess. If the user doesn't inspect the location bar they would be non the wiser, and pretty much any URL with the word google or facebook in it will probably look legit to a user. Omnifarious Omnifarious If you don't trust Google to do that, you shouldn't trust them with your data in the first place ;- — Joachim Sauer.
Joachim, Google is a large organization with a large codebase. It might be reasonable to trust gmail to keep your data safe, but not trust another part of Google to provide a UI that is clear and unspoofable. That said, the OAuth guys know how to design security protocols. The problem of coming up with a UI that makes clear to many different users from many different cultures what authority they're granting is still a topic of open research. Sign up or log in Sign up using Google.
0コメント