Commit Graph

3 Commits

Author SHA1 Message Date
cc4370c50d feat: Add runtime DNS-rebinding protection for blocklist HTTP connections
## Problem
The blocklist URL validation at create/update time has a TOCTOU (time-of-check-to-time-of-use) window.
An attacker can perform a DNS-rebinding attack where:
1. User adds blocklist URL pointing to attacker.com
2. At create time, attacker.com resolves to a public IP → validation passes
3. Later, when fetching, attacker.com resolves to 192.168.1.1 (internal network)
4. HTTP client connects to the private IP, potentially accessing internal services

## Solution
Add runtime destination IP validation at connection time via a custom socket factory:

- Created 'dns_validated_connector.py' with create_dns_validated_socket_factory() that validates
  all resolved IPs before socket creation
- HTTP session now uses the validated socket factory, protecting all blocklist imports globally
- Rejects connections to RFC 1918 private ranges, loopback, link-local, ULA, multicast, and
  reserved addresses (IPv4 and IPv6)
- Added comprehensive test coverage with 13 test cases

## Changes
- backend/app/services/dns_validated_connector.py: Custom socket factory with IP validation
- backend/app/startup.py: Use DNS-validated socket factory in HTTP session creation
- backend/app/utils/ip_utils.py: Updated docstring explaining runtime validation
- backend/app/services/blocklist_downloader.py: Updated module docstring
- backend/app/services/blocklist_service.py: Updated docstrings explaining two-layer protection
- backend/tests/test_services/test_dns_validated_connector.py: Test suite for socket factory
- Docs/Architekture.md: Added detailed section on DNS-rebinding protection

## Testing
- All 13 DNS validation tests pass
- All blocklist downloader tests pass (unaffected by changes)
- Linting: ruff, mypy pass with --strict
- Test coverage: 90% line coverage on dns_validated_connector.py

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
2026-04-29 19:10:51 +02:00
4ab767e3d4 TASK-009: Mitigate SSRF vulnerability in blocklist URL validation
- Change BlocklistSourceCreate.url from str to AnyHttpUrl (Pydantic type)
  - Rejects non-http schemes (file://, ftp://, etc.) at model boundary

- Add is_private_ip() utility to detect RFC 1918 private ranges:
  - 10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16 (RFC 1918)
  - 127.0.0.0/8, ::1/128 (loopback)
  - 169.254.0.0/16, fe80::/10 (link-local)
  - IPv6 site-local, multicast, and reserved ranges

- Add async validate_blocklist_url() function:
  - Resolves hostname via DNS using loop.run_in_executor()
  - Rejects if hostname resolves to private/reserved IP
  - Raises ValueError on validation failure

- Integrate validation into service layer:
  - create_source() calls validate_blocklist_url() before persist
  - update_source() conditionally validates if url provided
  - Both raise ValueError on failure

- Update router endpoints with error handling:
  - create_blocklist() and update_blocklist() catch ValueError
  - Return HTTP 400 Bad Request with descriptive error message

- Add comprehensive test coverage (9 new SSRF tests):
  - file://, ftp://, localhost, 127.0.0.1, 192.168.x.x
  - 10.x.x.x, 172.16.x.x, 169.254.x.x (link-local)
  - Valid public URLs (passes validation)
  - All 36 service tests passing

- Update documentation:
  - Features.md: Document URL validation constraints
  - Backend-Development.md: Add SSRF prevention pattern section

Fixes SSRF vulnerability where authenticated users could supply
file://, ftp://, or private IP URLs and the backend would fetch them.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
2026-04-26 12:57:23 +02:00
7392c930d6 feat: Stage 1 — backend and frontend scaffolding
Backend (tasks 1.1, 1.5–1.8):
- pyproject.toml with FastAPI, Pydantic v2, aiosqlite, APScheduler 3.x,
  structlog, bcrypt; ruff + mypy strict configured
- Pydantic Settings (BANGUI_ prefix env vars, fail-fast validation)
- SQLite schema: settings, sessions, blocklist_sources, import_log;
  WAL mode + foreign keys; idempotent init_db()
- FastAPI app factory with lifespan (DB, aiohttp session, scheduler),
  CORS, unhandled-exception handler, GET /api/health
- Fail2BanClient: async Unix-socket wrapper using run_in_executor,
  custom error types, async context manager
- Utility modules: ip_utils, time_utils, constants
- 47 tests; ruff 0 errors; mypy --strict 0 errors

Frontend (tasks 1.2–1.4):
- Vite + React 18 + TypeScript strict; Fluent UI v9; ESLint + Prettier
- Custom brand theme (#0F6CBD, WCAG AA contrast) with light/dark variants
- Typed fetch API client (ApiError, get/post/put/del) + endpoints constants
- tsc --noEmit 0 errors
2026-02-28 21:15:01 +01:00