DeepCode 1.2.0 Path Traversal via SPA Catch-All Route in main.py

Summary

DeepCode through commit c991dc2 contains a path traversal vulnerability in the SPA catch-all route in new_ui/backend/main.py that allows unauthenticated attackers to read arbitrary files by supplying percent-encoded path segments to the GET /{full_path:path} endpoint. Attackers can bypass Starlette's path normalization by encoding slashes as %2F and dots as %2E%2E, causing the joined path to traverse outside FRONTEND_DIST and exposing sensitive files such as SSH private keys, TLS certificates, and application secrets with a single HTTP request.