Key points of this writeup Discovered a leaked OAuth token: StaySafe.ph’s Facebook login redirect exposed a long-lived (~59-day) access token directly in the URL. That token alone was enough to impersonate a user, no password required. Reverse-engineered the mobile app: Decompiled ph.staysafe.mobileapp (v2.1) using Jadx and apktool to dig into how the app worked under the hood. Accessed sensitive exposure data: With just the leaked token, pulled detailed contact-tracing logs showing exposure status (Probable, Suspect, Confirmed, Cleared, Initial), color-coded and dated, including full historical records, not just current data. Mapped 20+ exposed API endpoints: Extracted from the app’s JS bundle, covering critical functions like password reset, OTP verification, account activation/deactivation, and account deletion. Found an exposed, editable backend: The Laravel backend source and admin panel were publicly accessible, and editable, leaking massive amounts of PII for millions of users: names, emails, passwords, phone numbers, OTPs, vaccination status, locations, and more. Technical Details During the pandemic, I found vulnerabilities in the StaySafe Android application: a user location disclosure issue, a full account takeover via access token, and admin panel access exposing millions of users’ PII.
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