Android Mastery¶

Android owns 70%+ of mobile market share
If you're doing mobile security testing or forensics you cannot avoid this platform where Linux kernel meets Java runtime in a sandboxed application model that creates unique security boundaries and exploitation opportunities

Why Android Security Matters

Application sandboxing via UID separation
Permission-based access control model
Rooting bypasses security boundaries (gaining shell)
Fragmentation creates endless configuration gaps
Mobile apps often expose APIs not tested like web apps
Data at rest encryption challenges

Android Security Architecture

The Android security model relies on several layers working together:

Linux Kernel - Standard Linux process isolation, filesystem permissions
Application Sandbox - Each app runs as a unique Linux user (UID)
Permissions - Apps declare required permissions in manifest
Application Signing - All APKs must be signed by developer key
Verified Boot - Chain of trust from bootloader to OS
SELinux - Mandatory access control enforced system-wide
Encryption - File-based encryption (FBE) since Android 7.0

The Fragmentation Problem

Android versions across devices vary wildly
Security patches delayed by OEMs for months or years
A Pixel device gets updates within weeks but budget devices might never see security patches past initial purchase. This creates a massive attack surface for targeted operations against older devices

ADB and Debugging

Android Debug Bridge is your primary tool for interaction. With USB debugging enabled or over TCP you can install apps , access shell , pull logs , and extract data. During penetration testing this is the main attack vector

adb devices                      # List connected devices
adb shell                        # Interactive shell
adb install app.apk              # Install APK
adb logcat                       # View device logs
adb pull /sdcard/data/           # Pull files from device
adb push file /sdcard/           # Push file to device