Automatic generation of inter-component communication exploits for Android applications

Although a wide variety of approaches identify vulnerabilities in Android apps, none attempt to determine exploitability of those vulnerabilities. Exploitability can aid in reducing false positives of vulnerability analysis, and can help engineers triage bugs. Specifically, one of the main attack vectors of Android apps is their inter-component communication interface, where apps may receive messages called Intents. In this paper, we provide the first approach for automatically generating exploits for Android apps, called LetterBomb, relying on a combined path-sensitive symbolic execution-based static analysis, and the use of software instrumentation and test oracles. We run LetterBomb on 10,000 Android apps from Google Play, where we identify 181 exploits from 835 vulnerable apps. Compared to a state-of-the-art detection approach for three ICC-based vulnerabilities, LetterBomb obtains 33%-60% more vulnerabilities at a 6.66 to 7 times faster speed.