1 / 21

Long Lu, Zhichun Li , Zhenyu Wu , Wenke Lee and Guofei Jiang

CHEX: Statically Vetting Android Apps for Component Hijacking Vulnerability. Long Lu, Zhichun Li , Zhenyu Wu , Wenke Lee and Guofei Jiang. V etting vulnerable apps in large scale. Accurate and scalable app vetting methods. Component hijacking vulnerability.

ronni
Download Presentation

Long Lu, Zhichun Li , Zhenyu Wu , Wenke Lee and Guofei Jiang

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. CHEX: Statically Vetting Android Apps for Component Hijacking Vulnerability Long Lu, Zhichun Li, Zhenyu Wu, WenkeLee and Guofei Jiang

  2. Vetting vulnerable apps in large scale Accurate and scalable app vetting methods Component hijacking vulnerability High volume of app submissions Inexperienced developers Large number of vulnerable apps CHEX: Statically Vetting Android Apps for Component Hijacking Vulnerabilities

  3. Components in Android apps App1 App2 Android Framework CHEX: Statically Vetting Android Apps for Component Hijacking Vulnerabilities

  4. What can go wrong? Unauthorized access to protected resources Contact Manager App • Enumerator • Service Android Framework Contacts CHEX: Statically Vetting Android Apps for Component Hijacking Vulnerabilities

  5. What can go wrong? Unauthorized access to private resources Contact Manager App Private Storage Android Framework • Setting Update • Receiver CHEX: Statically Vetting Android Apps for Component Hijacking Vulnerabilities

  6. Component hijacking attacks A class of attacks that seek to gain unauthorized access to protected or private resources through exported components in vulnerable apps. CHEX: Statically Vetting Android Apps for Component Hijacking Vulnerabilities

  7. Similar attacks and countermeasures CHEX: Statically Vetting Android Apps for Component Hijacking Vulnerabilities

  8. CHEX -- Component Hijacking Examiner Goal: Vetting large volumes of apps for component hijacking vulnerabilities CHEX CHEX: Statically Vetting Android Apps for Component Hijacking Vulnerabilities

  9. Analysis approach App Private Android Framework Protected • A data-flow perspective • Component hijacking  read/write protected or private data via exported components • Detecting component hijacking  finding “hijack-enabling flows” CHEX: Statically Vetting Android Apps for Component Hijacking Vulnerabilities

  10. Challenges CHEX: Statically Vetting Android Apps for Component Hijacking Vulnerabilities

  11. Dalysis: Dalvik Analysis Framework Meta data Parse manifest Point-to analysis Constants Instruction translation Abstract interpretation SSA conversion Call graph builder Disassemble bytecode (DexLib) SSA IR Class hierarchy SDG builder Instructions … Backend Frontend CHEX: Statically Vetting Android Apps for Component Hijacking Vulnerabilities Consumes off-the-shelf Android app package (.apk) Generates SSA IR (adopted from WALA) Supports extensible backend for multiple types analysis tasks

  12. Modeling Android Framework App Android Framework System managers Reflections Mixed languages Large codebase … Libraries Runtime • Design choice: model the framework • For data-flow analysis, we model • Asynchronous entry points • Framework-assisted data-flows CHEX: Statically Vetting Android Apps for Component Hijacking Vulnerabilities

  13. App entry points Definition: App entry points are the methods that are defined by the app and intended to be called only by the framework. • Points through which control transfers to the app • Start point • Callbacks CHEX: Statically Vetting Android Apps for Component Hijacking Vulnerabilities

  14. Entry point discovery Unused methods overriding framework Dead code Entry points • How to distinguish? • Containing class is instantiated • Original interface is never called by app Observation: only two ways to “register” entry points • Declaring them in the manifest file • Overriding/implementing the designated interfaces CHEX: Statically Vetting Android Apps for Component Hijacking Vulnerabilities

  15. Entry point discovery Unused methodsoverriding framework Entry points Unused methodsoverriding framework Entry points CHEX: Statically Vetting Android Apps for Component Hijacking Vulnerabilities

  16. App splitting Definition: A split is a subset of the app code that is reachable from an entry point. App Android Framework • Modeling app execution by permuting split executions in all feasible orders • Why reasonable? • Most splits cannot be interleaved • Efficient pruning techniques CHEX: Statically Vetting Android Apps for Component Hijacking Vulnerabilities

  17. SDS and PDS G1 Src1 • Split Data-flow Summary (SDS) • Intra-split data-flows that start and end at • heapvariables, sources, or sinks. Sink1 G1 Src1 G1 When permutation ends, all possible data-flows have been enumerated. Sink1 Permutation Data-flow Summary (PDS) • Linking two adjacent SDSs in a feasible permutation CHEX: Statically Vetting Android Apps for Component Hijacking Vulnerabilities

  18. Identifying “hijack-enabling flows” Input Sensitive Input Sensitive … … … Input-specified exit Public Critical Using descriptive policies to specify flows of interests CHEX: Statically Vetting Android Apps for Component Hijacking Vulnerabilities

  19. Evaluations • 5,486 apps from the official and alternative markets • Hardware spec: Intel Core i7-970 with 12GB RAM Performance Accuracy 254/5,486 flagged as vulnerable True positive rate: 81% • Median processing time: 37sec • 22% apps took >5min Insights • 50 entry points of 44 types per app • 99.7% apps contain inter-split data-flows CHEX: Statically Vetting Android Apps for Component Hijacking Vulnerabilities

  20. Case study CHEX: Statically Vetting Android Apps for Component Hijacking Vulnerabilities

  21. Conclusion CHEX: Statically Vetting Android Apps for Component Hijacking Vulnerabilities

More Related