Taxonomy of Security Weaknesses in Java and Kotlin Android Apps

TL;DR

This paper provides a comprehensive empirical analysis and taxonomy of security weaknesses in Java and Kotlin Android apps, comparing the types and frequencies of vulnerabilities in both languages.

Contribution

It introduces the first detailed taxonomy of security weaknesses in Java and Kotlin Android apps, based on manual analysis and developer surveys.

Findings

Identified common security weaknesses in Java and Kotlin Android apps.

Validated the taxonomy through a survey of Android developers.

Proposed future actions to enhance Android app security.

Abstract

Android is nowadays the most popular operating system in the world, not only in the realm of mobile devices, but also when considering desktop and laptop computers. Such a popularity makes it an attractive target for security attacks, also due to the sensitive information often manipulated by mobile apps. The latter are going through a transition in which the Android ecosystem is moving from the usage of Java as the official language for developing apps, to the adoption of Kotlin as the first choice supported by Google. While previous studies have partially studied security weaknesses affecting Java Android apps, there is no comprehensive empirical investigation studying software security weaknesses affecting Android apps considering (and comparing) the two main languages used for their development, namely Java and Kotlin. We present an empirical study in which we: (i) manually analyze 681 commits including security weaknesses fixed by developers in Java and Kotlin apps, with the goal of defining a taxonomy highlighting the types of software security weaknesses affecting Java and Kotlin Android apps; (ii) survey 43 Android developers to validate and complement our taxonomy. Based on our findings, we propose a list of future actions that could be performed by researchers and practitioners to improve the security of Android apps.