URI Hijacking

What the technique is

Adversaries may register Uniform Resource Identifiers (URIs) to intercept sensitive data. Applications regularly register URIs with the operating system to act as a response handler for various actions, such as logging into an app using an external account via single sign-on. This allows redirections to that specific URI to be intercepted by the application. If an adversary were to register for a URI that was already in use by a genuine application, the adversary may be able to intercept data intended for the genuine application or perform a phishing attack against the genuine application. Intercepted data may include OAuth authorization codes or tokens that could be used by the adversary to gain access to protected resources.

What MITRE says you would watch

• AN1693

  When vetting applications for potential security weaknesses, the vetting process could look for insecure use of Intents. Defenders should validate the entirety of the URI. For example, the URI's scheme should be https and the URI's host should be on a list of trusted hosts. Developers should be encouraged to use techniques to ensure that the intent can only be sent to an appropriate destination (e.g., use explicit rather than implicit intents, permission checking, checking of the destination app's signing certificate, or utilizing the App Links feature). For mobile applications using OAuth, encourage use of best practice. […]

• AN1694

  When vetting applications for potential security weaknesses, the vetting process could look for insecure use of Intents. Developers should be encouraged to use techniques to ensure that the intent can only be sent to an appropriate destination (e.g., use explicit rather than implicit intents, permission checking, checking of the destination app's signing certificate, or utilizing the App Links feature). For mobile applications using OAuth, encourage use of best practice.