# Sentinel's Journal

## 2026-02-07 - Telegram Bot Authorization Bypass
**Vulnerability:** The Telegram Deployment Bot (`scripts/telegram_deploy_bot.py`) contained a "Fail Open" vulnerability where omitting the `TELEGRAM_ALLOWED_USER_IDS` environment variable resulted in granting access to *all* Telegram users instead of *none*.
**Learning:** Security controls must default to deny (Fail Closed). Implicitly allowing access when configuration is missing creates silent vulnerabilities that are hard to detect until exploited.
**Prevention:** Ensure all authorization checks explicitly return `False` or throw an exception if the access control list is empty or undefined. Never default to `True` in security-critical paths.

## 2026-02-13 - [Documentation] Cloudflare Nameservers and Domain Unification
- Updated Cloudflare nameservers to daisy.ns.cloudflare.com and rocco.ns.cloudflare.com.
- Unified domain name to lengkundee01.org across CNAME and PWA documentation.

## 2026-02-14 - Web Dashboard Exception Leakage
**Vulnerability:** The web dashboard (`scripts/web_dashboard.py`) was catching generic `Exception` and returning `str(e)` directly to the user. This could expose sensitive internal details (stack traces, file paths, database errors) in the HTTP response.
**Learning:** Returning raw exception messages is a common but dangerous pattern. It prioritizes debugging convenience over security.
**Prevention:** Always catch exceptions, log the full details (including stack traces) to a secure log file, and return a generic "Internal Server Error" message to the client.