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Received β€” 9 April 2026 ⏭ /r/netsec - Information Security News & Discussion

Threat Model Discrepancy: Google Password Manager leaks cleartext passwords via Task Switcher (Won't Fix) - Violates German BSI Standards

Hi everyone, I’m a Cybersecurity student at HFU in Germany and recently submitted a vulnerability to the Google VRP regarding the Google Password Manager on Android (tested on Pixel 8, Android 16).

The Issue: When you view a cleartext password in the app and minimize it, the app fails to apply FLAG_SECURE or blur the background. When opening the "Recent Apps" (Task Switcher), the cleartext password is fully visible in the preview, even though the app actively overlays a "Enter your screen lock" biometric prompt in the foreground. It basically renders its own secondary biometric lock completely useless.

Google's Response: Google closed the report as Won't Fix (Intended Behavior). Their threat model assumes that if an attacker has physical access to an unlocked device, it's game over.

The BSI Discrepancy: What makes this interesting is that the German Federal Office for Information Security (BSI) recently published a study on Password Managers. In their Threat Model A02 ("Attacker has temporary access to the unlocked device"), they explicitly mandate that sensitive content MUST be protected from background snapshots/screenshots. So while Google says this is intended, national security guidelines classify this as a vulnerability. (For comparison: The iOS built-in password manager instantly blurs the screen when losing focus).

Here is my PoC screenshot:
https://drive.google.com/file/d/1PTGKRpyFj_jY9S76Jlo62mSCDJ3c6uLO/view?usp=sharing
https://drive.google.com/file/d/1nIJMQbM4R17EMt9f1Ffb4UmCPYY7-GXb/view?usp=sharing

What are your thoughts on this? Should password managers protect against shoulder surfing via the Task Switcher, or is Google right to rely solely on the OS lockscreen?

submitted by /u/Onat120
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