Hardcoded Android App Keys Can Expose Gemini API Access and User Files
Summary
CloudSEK found 32 hardcoded Google API keys with Gemini access across 22 popular Android apps. It confirmed that one key exposed files, including audio recordings, in the ELSA Speak project.
Key points
- CloudSEK found 32 live Gemini-enabled Google API keys in 22 apps from a scan of the 10,000 most-installed Android apps; the apps have more than 500 million combined installs.
- When Gemini is enabled on a Google Cloud project, existing API keys on that project may gain access to Gemini endpoints, even if they were originally embedded in apps for services such as Maps or Firebase.
- CloudSEK confirmed that a key in ELSA Speak exposed Gemini Files API metadata and accessible file URIs, including audio files described as likely user speech samples.
- The other 31 keys returned empty file stores during testing, but could still be used to make Gemini API calls, incur charges, exhaust quotas, or access data uploaded later.
- CloudSEK said it notified all 22 app developers and redacted the keys; its researchers reported making no write operations or data modifications.
- The article recommends auditing projects and key permissions, rotating keys embedded in published apps, and keeping sensitive API calls behind server-side controls.
Article Details
- Vulnerability Types
- Hardcoded API credentials exposed in mobile application packages
- Retroactive privilege escalation of existing Google API keys when the Generative Language API is enabled
- Exploitation Status
- active
- Exploit Availability
- unknown
- Patch Status
- unknown
- Workarounds
- Restrict API keys to the services they need and remove Generative Language API access unless required.
- Rotate keys embedded in published mobile application packages.
- Use a server-side proxy for mobile API calls instead of hardcoding API keys in app source code.
MITRE ATT&CK
Vendors
CloudSEKCloudSEK’s BeVigil - the world’s first mobile app security search engine - scanned the top 10,000 Android applications by number of installs to assess the mobile-app attack surface of this vulnerability. The findingsGoogleGoogle's API key architecture, originally designed for innocuous public-facing services like Maps, Firebase, and YouTube, was never meant to serve as authentication for sensitive AI systems. For over a decade, Google
Products
@Voice Aloud Reader (TTS)@Voice Aloud Reader (TTS)30 Day Fitness Challenge30 Day Fitness ChallengeAll Email Access: Mail InboxAll Email Access: Mail Inboxapna Job Search Appapna Job Search AppBeVigilCloudSEK’s BeVigil - the world’s first mobile app security search engine - scanned the top 10,000 Android applications by number of installs to assess the mobile-app attack surface of this vulnerability. The findingsCifra Club - ChordsCifra Club - ChordsELSA Speak English LearningELSA Speak English LearningGeminiThat changed with the arrival of Gemini. Now they are live credentials to one of the most powerful AI systems in the world.Generative Language APIIn February 2026, Truffle Security published research revealing that when the Gemini API (Generative Language API) is enabled on a Google Cloud project, every existing API key on that project silently gains access toGoogle API keysapplications ranked by number of installs. Using automated secret detection rules, we identified Google API keys of the AIza... format hardcoded in app packages, then verified each key against the Gemini API toGoogle Cloudpublished research revealing that when the Gemini API (Generative Language API) is enabled on a Google Cloud project, every existing API key on that project silently gains access to Gemini endpoints - with noGoogle Pay for BusinessGoogle Pay for BusinessHD Sticker & Pack WAStickersAppsHD Sticker & Pack WAStickersAppsISS Live Now: Live Earth ViewISS Live Now: Live Earth ViewJioSphere: Web BrowserJioSphere: Web BrowserKrishify: Farmer Community AppKrishify: Farmer Community AppMuslim: Ramadan 2026, AthanMuslim: Ramadan 2026, AthanOYO Hotel Booking AppOYO Hotel Booking AppPersonal Stickers StickerMakerPersonal Stickers StickerMakerShutterfly: Prints Cards GiftsShutterfly: Prints Cards GiftsTaobaoTaobaoTeachmint Connected ClassroomTeachmint Connected ClassroomTextSticker 2026 WAStickerAppsTextSticker 2026 WAStickerAppsTextSticker for WAStickerAppsTextSticker for WAStickerAppsThe Hindu: India & World NewsThe Hindu: India & World NewsVideo Maker & Photo MusicVideo Maker & Photo Music
Countries
JapanA small company in Japan was using the Gemini API exclusively to build a handful of internal productivity tools - not a public-facing product. Their implementation was protected by firewall-level IP access restrictions,MexicoA three-person development team in Mexico with a normal monthly Google Cloud spend of $180 found their API key compromised between February 11 and 12, 2025. Within 48 hours, the stolen key generated $82,314 in charges -