Privacy Issues with the Google Android Market Thorben Kr uger - - PowerPoint PPT Presentation

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Oct 23, 2022 157 likes •778 views

Privacy Issues with the Google Android Market Thorben Kr uger Bastiaan Wissingh benthor@os3.nl bastiaan@os3.nl February 2, 2011 1/ 18 Outline Introduction Terms Research I Background MITM Sniffing Findings Research II App Analysis

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Privacy Issues with the Google Android Market

Thorben Kr¨ uger Bastiaan Wissingh benthor@os3.nl bastiaan@os3.nl February 2, 2011

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Outline

Introduction Terms Research I Background MITM Sniffing Findings Research II App Analysis Findings Implications Bonus Conclusion

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Definition of Terms

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Definition of Terms

◮ Android

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Definition of Terms

◮ Android ◮ Google Android Market

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Definition of Terms

◮ Android ◮ Google Android Market ◮ XMPP

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Definition of Terms

◮ Android ◮ Google Android Market ◮ XMPP ◮ App

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Original Question

Google Android Market - Remotely Controllable?

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Original Question

Google Android Market - Remotely Controllable?

◮ To what exact extent?

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Original Question

Google Android Market - Remotely Controllable?

◮ To what exact extent?

◮ Suspicion: Highly Privileged Remove Administration

Functionality

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Original Question

Google Android Market - Remotely Controllable?

◮ To what exact extent?

◮ Suspicion: Highly Privileged Remove Administration

Functionality

◮ What Privacy Issues?

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Original Question

Google Android Market - Remotely Controllable?

◮ To what exact extent?

◮ Suspicion: Highly Privileged Remove Administration

Functionality

◮ What Privacy Issues? ◮ Proposed Mitigations?

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Current Research: Status

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Current Research: Status

◮ Market uses XMPP over SSL

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Current Research: Status

◮ Market uses XMPP over SSL ◮ Google Android: A State-of-the-Art Review of Security

Mechanisms

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Current Research: Status

◮ Market uses XMPP over SSL ◮ Google Android: A State-of-the-Art Review of Security

Mechanisms

◮ AppBrain

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Approach: SSL Man-In-The-Middle

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Approach: SSL Man-In-The-Middle

◮ Idea: Traffic Introspection

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Approach: SSL Man-In-The-Middle

◮ Idea: Traffic Introspection ◮ Methods: Lots Of Dirty Hacks

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Traffic Analysis: Results

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Traffic Analysis: Results

◮ Confirmed: XMPP-Triggered Installation

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Traffic Analysis: Results

◮ Confirmed: XMPP-Triggered Installation ◮ Unconfirmed: Additional Functionality

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Approach: Reverse Engineering

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Approach: Reverse Engineering

◮ Analyze Market Package

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Approach: Reverse Engineering

◮ Analyze Market Package ◮ Core System Application

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Binary Analysis: Findings

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Binary Analysis: Findings

◮ Binary Decodable To “Assembly”

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Binary Analysis: Findings

◮ Binary Decodable To “Assembly” ◮ Results Hardly Readable

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Binary Analysis: Findings

◮ Binary Decodable To “Assembly” ◮ Results Hardly Readable ◮ Evidence: Remotely Triggerable Functionality

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Binary Analysis: Findings

◮ Binary Decodable To “Assembly” ◮ Results Hardly Readable ◮ Evidence: Remotely Triggerable Functionality

◮ INSTALL ASSET ◮ REMOVE ASSET 9/ 18

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Binary Analysis: Findings

◮ Binary Decodable To “Assembly” ◮ Results Hardly Readable ◮ Evidence: Remotely Triggerable Functionality

◮ INSTALL ASSET ◮ REMOVE ASSET

◮ Evidence: Persistent Connection

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Privacy Implications

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Privacy Implications

◮ No Evidence For: Advanced Remote Control Functionality

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Privacy Implications

◮ No Evidence For: Advanced Remote Control Functionality ◮ Possible Issue For Some: Remotely Triggered Application

Removal

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Mitigation Idea: Patch Script

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Mitigation Idea: Patch Script

◮ “Assembly” Rebuildable To Binary

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Mitigation Idea: Patch Script

◮ “Assembly” Rebuildable To Binary ◮ Result Still Executable

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Mitigation Idea: Patch Script

◮ “Assembly” Rebuildable To Binary ◮ Result Still Executable ◮ Assembly-Level Patch: Remove Unwanted Functionality

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Accidental Finding: Market App Honors Permission System

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Accidental Finding: Market App Honors Permission System

◮ Error For Patched Market: No Permission To Install Apps

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Accidental Finding: Market App Honors Permission System

◮ Error For Patched Market: No Permission To Install Apps ◮ Very Unexpected

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Digression: Android Permission System

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Digression: Android Permission System

◮ Central Part Of Android Architecture

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Digression: Android Permission System

◮ Central Part Of Android Architecture ◮ Open Source!

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Digression: Android Permission System

◮ Central Part Of Android Architecture ◮ Open Source! ◮ Uses: Plain XML Files

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Digression: Android Permission System

◮ Central Part Of Android Architecture ◮ Open Source! ◮ Uses: Plain XML Files ◮ Problem: Very Coarse Grained UI

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Android Permission System: Current Research

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Android Permission System: Current Research

◮ permissionBlocker.apk

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Android Permission System: Current Research

◮ permissionBlocker.apk ◮ Apex

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Proposal: Extension of Apex

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Proposal: Extension of Apex

◮ Requires: Changes To Software Stack

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Proposal: Extension of Apex

◮ Requires: Changes To Software Stack ◮ Hurdle: System App Permissions Handled Differently

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Proposal: Extension of Apex

◮ Requires: Changes To Software Stack ◮ Hurdle: System App Permissions Handled Differently ◮ Red Tape: Nothing Has Been Released

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Conclusion

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Conclusion

◮ Current Market App Less Evil Than Expected

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Conclusion

◮ Current Market App Less Evil Than Expected ◮ Binary/Assembly Patches Possible

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Conclusion

◮ Current Market App Less Evil Than Expected ◮ Binary/Assembly Patches Possible ◮ Alternative Approach: Permission Management

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Outlook

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Outlook

◮ Reimplement Apex: NLnet funding?

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Questions?

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