# SSRF Analysis Report

## 1. Executive Summary
- **Analysis Status:** Complete
- **Key Outcome:** **ZERO exploitable SSRF vulnerabilities identified.** This Flask application performs no outbound HTTP requests and has no mechanisms for user input to influence server-side network operations.
- **Purpose of this Document:** This report provides comprehensive evidence that the application has no SSRF attack surface. All network-accessible endpoints were systematically analyzed, and no HTTP client usage, URL fetching, or request-making capabilities were discovered.

## 2. Dominant Vulnerability Patterns

### Pattern Analysis: No SSRF Patterns Found

After systematic analysis of all 4 network-accessible endpoints and comprehensive code review, **NO SSRF vulnerability patterns were identified**.

**Key Findings:**
- Application performs zero outbound HTTP/HTTPS requests
- No HTTP client libraries imported or used (requests, urllib, httpx, aiohttp, etc.)
- All redirects are internal Flask routes using `url_for()` with no user-controllable destinations
- PhantomJS is installed in Docker container but completely unused in application code
- No subprocess execution or command injection vectors that could be leveraged for SSRF
- No webhook handlers, callback URLs, or external API integrations
- No SSO/OIDC discovery endpoints or JWKS fetching
- No image processing, link unfurling, or media rendering from URLs

## 3. Strategic Intelligence for Exploitation

### Application Architecture (SSRF Perspective)

**HTTP Client Library:** None - application uses no outbound HTTP capabilities
**Request Architecture:** Inbound-only web server with no external service dependencies
**Internal Services:** Single monolithic Flask application with no internal service communication
**Network Isolation:** Application makes zero outbound network connections

### Endpoint Analysis Summary

| Endpoint | HTTP Method | User Input | Network Operations | SSRF Risk |
|----------|-------------|-----------|-------------------|-----------|
| `/` | GET | None | Internal redirect to `/login` | None |
| `/login` | GET/POST | `username`, `password` | Local authentication (in-memory dict lookup) | None |
| `/profile` | GET | JWT token (cookie) | JWT decode, template rendering | None |
| `/dashboard` | GET | JWT token (cookie) | Environment variable read, authorization check | None |

### Technology Stack Analysis

**Web Framework:** Flask 3.0.3 with Werkzeug 3.0.3
**Dependencies:** PyJWT, Jinja2, cryptography (unused)
**Network Operations:** 
- Inbound: HTTP server on port 5003 (0.0.0.0 binding)
- Outbound: **ZERO** - no external connections made

### PhantomJS Analysis

**Installation Status:** Installed in Docker container via Dockerfile line 12
**Usage Status:** **COMPLETELY UNUSED** - no invocation in application code
**Security Note:** PhantomJS is an abandoned project (last release 2016) with known CVEs. While it could theoretically be used for SSRF if invoked with user-controlled URLs, the application never executes it.
**Recommendation:** Remove from Dockerfile to reduce attack surface

## 4. Secure by Design: Validated Components

The following components were analyzed and found to have no SSRF vulnerabilities. All are low-priority for SSRF testing.

| Component/Flow | Endpoint/File Location | Defense Mechanism Implemented | Verdict |
|---|---|---|---|
| Root Redirect | `app.py:16-18` (GET /) | Uses Flask `url_for('login')` for internal routing only | SAFE - No user input, no outbound requests |
| Login Authentication | `app.py:20-35` (POST /login) | In-memory dictionary lookup with no external calls | SAFE - No HTTP client usage |
| Profile Page | `app.py:37-52` (GET /profile) | JWT decode and template rendering, no external requests | SAFE - No outbound network operations |
| Admin Dashboard | `app.py:54-69` (GET /dashboard) | Environment variable read (`os.getenv`), no network calls | SAFE - No URL fetching or HTTP requests |
| All Redirects | `app.py:18,29,41,58` | Flask `redirect(url_for(...))` with hardcoded route names | SAFE - No user-controlled redirect destinations |

### Comprehensive SSRF Sink Search Results

**HTTP Client Libraries Checked:**
- ✅ `requests` - NOT FOUND
- ✅ `urllib`, `urllib2`, `urllib3` - NOT FOUND
- ✅ `httplib`, `http.client` - NOT FOUND
- ✅ `aiohttp`, `httpx`, `pycurl` - NOT FOUND

**URL Operations Checked:**
- ✅ `urlopen()` - NOT FOUND
- ✅ `file_get_contents()` - NOT FOUND
- ✅ URL-based file inclusion - NOT FOUND

**Subprocess/Command Execution Checked:**
- ✅ `subprocess.call/run/Popen` - NOT FOUND
- ✅ `os.popen()`, `os.system()` - NOT FOUND
- ✅ Shell command execution (`curl`, `wget`) - NOT FOUND
- ⚠️ `os.getenv()` at line 64 - SAFE (read-only environment variable access)

**Specialized SSRF Vectors Checked:**
- ✅ Headless browsers (Puppeteer, Playwright, Selenium) - NOT FOUND
- ⚠️ PhantomJS - INSTALLED BUT NEVER INVOKED
- ✅ Media processors (ImageMagick, FFmpeg) - NOT FOUND
- ✅ Link preview/unfurling - NOT FOUND
- ✅ SSO/OIDC discovery endpoints - NOT FOUND
- ✅ JWKS fetching - NOT FOUND
- ✅ Webhook handlers - NOT FOUND
- ✅ External API integrations - NOT FOUND

### Analysis Methodology

**Backward Taint Analysis:** Not applicable - no SSRF sinks identified to trace backward from

**Code Review Approach:**
1. Examined all 4 network-accessible endpoints for HTTP client usage
2. Searched entire codebase for HTTP client library imports
3. Analyzed all `os` module usage (only `os.getenv` found - safe)
4. Reviewed redirect implementations (all internal Flask routes)
5. Checked for subprocess execution capabilities
6. Verified PhantomJS installation status and usage
7. Confirmed zero outbound network traffic capability

## 5. Summary and Conclusion

**SSRF Attack Surface: ZERO**

This Flask application is a deliberately vulnerable CTF challenge focused on **JWT authentication bypass vulnerabilities**, not SSRF. The application architecture is completely self-contained with:
- No outbound HTTP requests
- No external service dependencies
- No user-controllable URL parameters
- No mechanisms for server-side request forgery

**Primary Vulnerability Class:** Authentication/Authorization (JWT algorithm confusion with `algorithm='none'`)
**SSRF Vulnerability Class:** Not applicable to this application

**Recommendation for Exploitation Phase:** Focus exclusively on JWT forgery and authentication bypass. No SSRF exploitation attempts are warranted.