Uninitialized Use Information Disclosure in Chrome ANGLE

This is a small standalone Python proof-of-concept repository containing two code files: a deliberately vulnerable Flask/Jinja2 application (vulnerable_app.py) and a matching exploit script (exploit_ssti_attr.py). The vulnerable app exposes a single web route '/' and reads the 'name' query parameter, then unsafely embeds it into a template string passed to render_template_string, creating a classic server-side template injection condition. The exploit script sends a GET request to http://localhost:5000/ with a Jinja2 payload that uses the |attr filter to access __class__, __mro__, __getitem__, and __subclasses__(), demonstrating bypass of simplistic keyword filtering and exposing Python internals. The returned response is truncated and printed, showing subclass enumeration that could be used to progress toward RCE primitives such as os.popen. Repository structure is minimal: LICENSE, README.md, exploit_ssti_attr.py, and vulnerable_app.py. This is a real exploit POC rather than a detection script, but it is not fully weaponized because it does not include automated command execution or a customizable post-exploitation payload.