Exercise 3

Application is leaking data - Fix in Smali

Process

• Extract data from apk with apktool: apktool d app-release.apk

• Fix the smali code.

• Repackage the apk: apktool b app-release

The issue

• Clear the log: adb logcat -c

• Filter by pid; adb logcat --pid=$(adb shell pidof pt.ua.deti.hello)

• Ignore all processes, except for tag hello: adb logcat -s "*:S hello"

Offending code

app-release/smali/pt/ua/deti/hello/MainActivity.smali

The fix

Deploy

• apktool b app-release --use-aapt2

• java -jar uber-apk-signer-1.2.1.jar --apks app-release/dist/app-release.apk

• adb uninstall pt.ua.deti.hello

• adb install app-release/dist/app-release-alisigned-debugSigned.apk

Verification

• adb logcat -s "*:S hello"