The impact of vendor customizations on android security

The smartphone market has grown explosively in recent years, as more and more consumers are attracted to the sensor-studded multipurpose devices. Android is particularly ascendant; as an open platform, smartphone manufacturers are free to extend and modify it, allowing them to differentiate themselves from their competitors. However, vendor customizations will inherently impact overall Android security and such impact is still largely unknown. In this paper, we analyze ten representative stock Android images from five popular smartphone vendors (with two models from each vendor). Our goal is to assess the extent of security issues that may be introduced from vendor customizations and further determine how the situation is evolving over time. In particular, we take a three-stage process: First, given a smartphone's stock image, we perform provenance analysis to classify each app in the image into three categories: apps originating from the AOSP, apps customized or written by the vendor, and third-party apps that are simply bundled into the stock image. Such provenance analysis allows for proper attribution of detected security issues in the examined Android images. Second, we analyze permission usages of pre-loaded apps to identify overprivileged ones that unnecessarily request more Android permissions than they actually use. Finally, in vulnerability analysis, we detect buggy pre-loaded apps that can be exploited to mount permission re-delegation attacks or leak private information. Our evaluation results are worrisome: vendor customizations are significant on stock Android devices and on the whole responsible for the bulk of the security problems we detected in each device. Specifically, our results show that on average 85.78% of all pre-loaded apps in examined stock images are overprivileged with a majority of them directly from vendor customizations. In addition, 64.71% to 85.00% of vulnerabilities we detected in examined images from every vendor (except for Sony) arose from vendor customizations. In general, this pattern held over time -- newer smartphones, we found, are not necessarily more secure than older ones.

[1]  Yang Tang,et al.  CleanOS: Limiting Mobile Data Exposure with Idle Eviction , 2012, OSDI.

[2]  Alastair R. Beresford,et al.  MockDroid: trading privacy for application functionality on smartphones , 2011, HotMobile '11.

[3]  Ross J. Anderson,et al.  Aurasium: Practical Policy Enforcement for Android Applications , 2012, USENIX Security Symposium.

[4]  Yajin Zhou,et al.  Fast, scalable detection of "Piggybacked" mobile applications , 2013, CODASPY.

[5]  Christopher Krügel,et al.  Polymorphic Worm Detection Using Structural Information of Executables , 2005, RAID.

[6]  Yajin Zhou,et al.  Taming Information-Stealing Smartphone Applications (on Android) , 2011, TRUST.

[7]  Patrick Traynor,et al.  MAST: triage for market-scale mobile malware analysis , 2013, WiSec '13.

[8]  Swarat Chaudhuri,et al.  A Study of Android Application Security , 2011, USENIX Security Symposium.

[9]  Mirko Lahl.  Samsung Galaxy S3 , 2012 .

[10]  Heng Yin,et al.  DroidScope: Seamlessly Reconstructing the OS and Dalvik Semantic Views for Dynamic Android Malware Analysis , 2012, USENIX Security Symposium.

[11]  Lujo Bauer,et al.  Modeling and Enhancing Android's Permission System , 2012, ESORICS.

[12]  Shashi Shekhar,et al.  QUIRE: Lightweight Provenance for Smart Phone Operating Systems , 2011, USENIX Security Symposium.

[13]  Christopher Krügel,et al.  PiOS: Detecting Privacy Leaks in iOS Applications , 2011, NDSS.

[14]  Yajin Zhou,et al.  Detecting repackaged smartphone applications in third-party android marketplaces , 2012, CODASPY '12.

[15]  Helen J. Wang,et al.  Permission Re-Delegation: Attacks and Defenses , 2011, USENIX Security Symposium.

[16]  Zhen Huang,et al.  PScout: analyzing the Android permission specification , 2012, CCS.

[17]  Yajin Zhou,et al.  Systematic Detection of Capability Leaks in Stock Android Smartphones , 2012, NDSS.

[18]  Hao Chen,et al.  Attack of the Clones: Detecting Cloned Applications on Android Markets , 2012, ESORICS.

[19]  Paul C. van Oorschot,et al.  A methodology for empirical analysis of permission-based security models and its application to android , 2010, CCS '10.

[20]  Steve Hanna,et al.  Android permissions demystified , 2011, CCS '11.

[21]  Xuxian Jiang,et al.  AppInk: watermarking android apps for repackaging deterrence , 2013, ASIA CCS '13.

[22]  Zhuoqing Morley Mao,et al.  AppProfiler: a flexible method of exposing privacy-related behavior in android applications to end users , 2013, CODASPY.

[23]  David A. Wagner,et al.  Analyzing inter-application communication in Android , 2011, MobiSys '11.

[24]  David A. Wagner,et al.  AdDroid: privilege separation for applications and advertisers in Android , 2012, ASIACCS '12.

[25]  Jeremy Andrus,et al.  Cells: a virtual mobile smartphone architecture , 2011, SOSP '11.

[26]  Yajin Zhou,et al.  Hey, You, Get Off of My Market: Detecting Malicious Apps in Official and Alternative Android Markets , 2012, NDSS.

[27]  Yajin Zhou,et al.  Detecting Passive Content Leaks and Pollution in Android Applications , 2013, NDSS.

[28]  Norman Hardy,et al.  The Confused Deputy: (or why capabilities might have been invented) , 1988, OPSR.

[29]  Yajin Zhou,et al.  RiskRanker: scalable and accurate zero-day android malware detection , 2012, MobiSys '12.

[30]  Ninghui Li,et al.  Using probabilistic generative models for ranking risks of Android apps , 2012, CCS.

[31]  Xuxian Jiang,et al.  Unsafe exposure analysis of mobile in-app advertisements , 2012, WISEC '12.

[32]  Patrick D. McDaniel,et al.  On lightweight mobile phone application certification , 2009, CCS.

[33]  Dan S. Wallach,et al.  Longitudinal Analysis of Android Ad Library Permissions , 2013, ArXiv.

[34]  Yajin Zhou,et al.  Dissecting Android Malware: Characterization and Evolution , 2012, 2012 IEEE Symposium on Security and Privacy.

[35]  Ahmad-Reza Sadeghi,et al.  Towards Taming Privilege-Escalation Attacks on Android , 2012, NDSS.

[36]  Shashi Shekhar,et al.  AdSplit: Separating Smartphone Advertising from Applications , 2012, USENIX Security Symposium.

[37]  Seungyeop Han,et al.  These aren't the droids you're looking for: retrofitting android to protect data from imperious applications , 2011, CCS '11.

[38]  Kang G. Shin,et al.  Large-scale malware indexing using function-call graphs , 2009, CCS.

[39]  Wenke Lee,et al.  CHEX: statically vetting Android apps for component hijacking vulnerabilities , 2012, CCS.

[40]  Xinwen Zhang,et al.  Apex: extending Android permission model and enforcement with user-defined runtime constraints , 2010, ASIACCS '10.

[41]  Matthias Lange,et al.  L4Android: a generic operating system framework for secure smartphones , 2011, SPSM '11.

[42]  Byung-Gon Chun,et al.  TaintDroid: An Information-Flow Tracking System for Realtime Privacy Monitoring on Smartphones , 2010, OSDI.

[43]  Ahmad-Reza Sadeghi,et al.  MoCFI: A Framework to Mitigate Control-Flow Attacks on Smartphones , 2012, NDSS.

[44]  Ninghui Li,et al.  Android permissions: a perspective combining risks and benefits , 2012, SACMAT '12.