Hardcoded Google API Keys in Top Android Apps Now Expose Gemini AI

Google’s long-standing public API key format (AIza…) was silently elevated to grant access to the Gemini Generative Language API whenever Gemini is enabled on a Google Cloud project, turning keys embedded in mobile apps into live AI credentials. CloudSEK’s BeVigil scan of the top 10,000 Android apps found 32 live keys across 22 high-install apps (500M+ installs) with confirmed file exposure in ELSA Speak. #Gemini #ELSA

Keypoints

Google’s single API key format (AIza…) was historically treated as a public identifier but now gains sensitive Gemini access retroactively when Gemini is enabled on the project.
Truffle Security documented a silent privilege escalation: pre-existing public API keys silently gained access to Gemini endpoints with no warning or confirmation to developers.
CloudSEK’s BeVigil scanned the top 10,000 Android apps and identified 32 live Google API keys across 22 unique applications with a combined install base exceeding 500 million users.
BeVigil confirmed active data exposure in ELSA Speak: audio/mpeg user speech samples, file URIs, file sizes, timestamps, and SHA-256 hashes were retrievable via the Gemini Files API.
Exposed keys allow attackers to access stored files, make arbitrary Gemini API calls (incurring large charges), exhaust quotas, and disrupt AI services; real-world cases show catastrophic billing impacts.
Recommended mitigations include auditing GCP projects for Generative Language API enablement, rotating and restricting keys, never hardcoding keys in mobile apps, using server-side proxies, and scanning APKs with BeVigil.

MITRE Techniques

[T0000 ] No MITRE ATT&CK techniques explicitly mentioned – ‘No MITRE techniques were specified in the article.’

Indicators of Compromise

[API Key ] Hardcoded Google API keys embedded in APK packages – example: ‘AIza…’ (Google API key format), and 31 other live keys found across 22 apps
[File Hashes ] SHA-256 hashes listed in Gemini Files metadata (evidence of uploaded files) – example: SHA-256 values returned in file metadata (exact hashes redacted), and other hashes
[File URIs / File types ] Accessible file URIs and media types exposed via the Gemini Files API – example: audio/mpeg user speech samples, file URIs returned by the /files endpoint
[App Package ID ] Vulnerable Android package identifiers containing hardcoded keys – example: com.oyo.consumer, com.google.android.apps.nbu.paisa.merchant (and 20+ other package IDs)