StartFlagExploit

The ActivityManagerService (https://androidreverse.wordpress.com/2018/03/11/aosp-activitymanager-and-activitymanagerservice/) is a component of Android that manages the Running Applications, non-system Services, ContentProviders and much more. The StartFlag DoS Exploit sends a manipulated startActivity event telling to start another Application in "native debugging" mode (in our Test we use the PermissionGrant Activtiy wich is marked as not debuggable". A bug in the ActivityManagerService doesn't answer with forwarding a SecurityException to the Attacker, instead it throws the SecurityException without catching it. This causes the ActivityManagerService to crash and all other Services depending on it also die.