In their study, David Schmidt, Sebastian Schrittwieser, and Edgar Weippl analyzed 10,331 Android and iOS applications to examine how sensitive data such as API keys and cryptographic material is embedded in binaries and app bundles. Their results show that apps from both ecosystems leak secrets, with iOS apps showing a higher tendency to expose sensitive data. They also found that while developers remove secrets in later versions, they frequently forget to revoke the credentials, leaving them open to misuse.
David Schmidt presented the paper on October 15, 2025, at ACM CCS in Taipei, Taiwan.
Abstract
Mobile apps store various types of secrets to support their functionalities. These include API keys, and cryptographic material to authenticate users and access backend services. Once distributed, attackers can reverse-engineer the apps, and these secrets become accessible, posing risks such as data leaks, and service abuse.
In this paper, we conduct a large-scale analysis of 10,331 Android and iOS apps to study how secrets are embedded in mobile apps. Our methodology involves extracting and validating credentials from app bundles and comparing the types and frequency of embedded secrets across Android and iOS to identify systematic differences between the two ecosystems. To assess temporal dynamics, we re-analyze apps released in 2023 after their updates in 2024.
Our findings show that apps not only leak secrets required for functionality but also unintentionally include sensitive information like markdown documentation, and dependency management files.
We discovered 416 functional credentials across 65 services, including 13 Git credentials that grant access to 218 public and 2,440 private repositories. Our analysis reveals that iOS apps are more likely to expose secrets, although information leaks exist in both Android and iOS apps. Finally, we show that even if developers remove embedded credentials in later versions, they frequently forget to revoke them, leaving the credentials exploitable.
Links
Research Paper:
Leaky Apps: Large-scale Analysis of Secrets Distributed in Android and iOS Apps