Imagine walking through an ancient maze, each turn revealing hidden pathways and secrets. In the world of Android, the Binder framework serves as a similar maze, facilitating inter-process communication. Our recent exploration into this intricate web has not only provided a deeper understanding but also uncovered significant vulnerabilities. Join us as we navigate the labyrinth of the Android Binder Attack Matrix, uncovering the results of our investigation and what lies ahead.
Results
Achieving 68% Line Coverage
Our first milestone was achieving 68% line coverage. This achievement is akin to mapping a substantial portion of our ancient maze. By utilizing advanced tools and meticulous strategies, we managed to traverse and document the pathways within the Binder framework, ensuring a comprehensive understanding of its architecture.
Code Example:
# Command to measure code coverage
kcov --include-path=/path/to/binder/code --output-directory=coverage /path/to/binaryThis code snippet demonstrates how we measured the code coverage of our Binder fuzzing, providing a quantitative metric of our exploration.
Discovering CVE-2023–20938 & CVE-2023–21255
Two significant vulnerabilities were uncovered by Eugene Rodionov, Zi Fan Tan, Gulshan Singh: CVE-2023–20938 and CVE-2023–21255. These vulnerabilities are like hidden traps within the maze, posing potential risks if left unaddressed.
- CVE-2023–20938: A flaw in the Binder transaction mechanism that could allow privilege escalation.
- CVE-2023–21255: A race condition in the Binder driver leading to potential denial of service attacks.
Discovering these CVEs was like finding cracks in the foundation of a grand structure. Addressing these vulnerabilities is crucial to ensuring the stability and security of the entire system.
Future Work: Charting New Territories
Our exploration is far from over. The maze of Binder offers numerous unexplored pathways and potential discoveries.
Upstream Binder Fuzzer to GitHub.com/lkl/Linux
Our next step is to upstream the Binder Fuzzer to the GitHub repository lkl/Linux. This will allow the broader security community to benefit from our tools and insights, enhancing collaborative efforts to secure the Android ecosystem.
Code Example:
# Command to upstream Binder Fuzzer
git remote add upstream https://github.com/lkl/linux.git
git push upstream masterExplore Thread Interleaving Information
Adding thread interleaving information into our fuzzing engine is akin to adding a new dimension to our map. This will provide a more detailed view of the concurrency issues within Binder, leading to more robust vulnerability detection.
Improve Syzkaller Binder Code Coverage
Enhancing the Syzkaller Binder code coverage involves tackling complex challenges, much like solving advanced puzzles within our maze. This will involve refining our strategies and tools to cover even the most elusive paths within the Binder framework.
Tools: The Adventurer’s Kit
Our journey through the Binder maze was facilitated by an array of advanced tools, each serving a unique purpose.
linux-exploit-dev-env
A versatile environment for exploit development, supporting both x86_64 and arm64 architectures. This was our primary tool for setting up and conducting our Binder exploration.
pwndbg (slab, pcp, binder plugin)
These plugins were essential for inspecting various states within the Binder framework. Think of them as our magnifying glasses, allowing us to scrutinize intricate details and uncover hidden vulnerabilities.
bpftrace Scripts
These scripts were our tracking tools, tracing SLAB and page allocations to facilitate heap grooming and cross-cache attacks. They helped us keep an eye on critical allocation patterns and detect anomalies.
Conclusion: The Journey Continues
Our exploration of the Android Binder framework has been both challenging and rewarding. We’ve mapped out significant portions of the Binder maze, uncovered critical vulnerabilities, and laid the groundwork for future exploration. But like any great journey, this is just the beginning. As we continue to chart new territories and refine our tools, we invite the security community to join us in this adventure. Together, we can ensure that the Android ecosystem remains a secure and resilient platform for all.
Stay tuned for our next updates and discoveries. The maze of Binder holds many more secrets, and we’re just getting started. Good Luck for now!
