Visible to the public Biblio

Filters: Author is Aafer, Yousra  [Clear All Filters]
2019-02-08
Aafer, Yousra, Tao, Guanhong, Huang, Jianjun, Zhang, Xiangyu, Li, Ninghui.  2018.  Precise Android API Protection Mapping Derivation and Reasoning. Proceedings of the 2018 ACM SIGSAC Conference on Computer and Communications Security. :1151-1164.

The Android research community has long focused on building an Android API permission specification, which can be leveraged by app developers to determine the optimum set of permissions necessary for a correct and safe execution of their app. However, while prominent existing efforts provide a good approximation of the permission specification, they suffer from a few shortcomings. Dynamic approaches cannot generate complete results, although accurate for the particular execution. In contrast, static approaches provide better coverage, but produce imprecise mappings due to their lack of path-sensitivity. In fact, in light of Android's access control complexity, the approximations hardly abstract the actual co-relations between enforced protections. To address this, we propose to precisely derive Android protection specification in a path-sensitive fashion, using a novel graph abstraction technique. We further showcase how we can apply the generated maps to tackle security issues through logical satisfiability reasoning. Our constructed maps for 4 Android Open Source Project (AOSP) images highlight the significance of our approach, as \textasciitilde41% of APIs' protections cannot be correctly modeled without our technique.

2019-01-21
Choi, Hongjun, Lee, Wen-Chuan, Aafer, Yousra, Fei, Fan, Tu, Zhan, Zhang, Xiangyu, Xu, Dongyan, Deng, Xinyan.  2018.  Detecting Attacks Against Robotic Vehicles: A Control Invariant Approach. Proceedings of the 2018 ACM SIGSAC Conference on Computer and Communications Security. :801–816.
Robotic vehicles (RVs), such as drones and ground rovers, are a type of cyber-physical systems that operate in the physical world under the control of computing components in the cyber world. Despite RVs' robustness against natural disturbances, cyber or physical attacks against RVs may lead to physical malfunction and subsequently disruption or failure of the vehicles' missions. To avoid or mitigate such consequences, it is essential to develop attack detection techniques for RVs. In this paper, we present a novel attack detection framework to identify external, physical attacks against RVs on the fly by deriving and monitoring Control Invariants (CI). More specifically, we propose a method to extract such invariants by jointly modeling a vehicle's physical properties, its control algorithm and the laws of physics. These invariants are represented in a state-space form, which can then be implemented and inserted into the vehicle's control program binary for runtime invariant check. We apply our CI framework to eleven RVs, including quadrotor, hexarotor, and ground rover, and show that the invariant check can detect three common types of physical attacks – including sensor attack, actuation signal attack, and parameter attack – with very low runtime overhead.