Hey r/netsecstudents,
I’ve been building a local-first health data tool (Leo Health) and would really value security-focused feedback on the design.
The app parses Apple Health exports and Whoop CSVs into a local SQLite database and serves a localhost dashboard. The goal is to keep sensitive biometric data entirely on-device.
Dashboard binds to localhost
No outbound network requests by design
Python stdlib only (no runtime deps)
SAX parsing for Apple Health XML
Explicit SQL identifier allowlist
Docker image runs as non-root
Persistent data stored in user-owned directory
Security headers applied to dashboard responses
Threat model assumes a single-user trusted machine and explicitly does not treat localhost as a strong security boundary.
Localhost exposure assumptions
Parser hardening against malformed exports
Container security posture
SQLite handling risks
Any obvious footguns I may be missing
Repo:
https://github.com/sandseb123/Leo-Health-Core
Security policy is in SECURITY.md.
Appreciate any critique — happy to dig into implementation details.