# SSRF Analysis Report

## 1. Executive Summary
- **Analysis Status:** Complete
- **Key Outcome:** No Server-Side Request Forgery (SSRF) vulnerabilities identified. The application is entirely self-contained with zero outbound HTTP request functionality.
- **Purpose of this Document:** This report provides comprehensive documentation that the FastAPI job board application does not make server-side requests to external resources, eliminating SSRF as an attack vector.

## 2. Dominant Vulnerability Patterns

### No SSRF Patterns Identified

After systematic analysis of all network-accessible endpoints and code paths, **zero SSRF vulnerability patterns** were discovered. The application architecture is inherently resistant to SSRF attacks due to the following characteristics:

1. **No HTTP Client Usage:** Despite having `httpx==0.27.0` installed in requirements.txt, the library is never imported or used in the application code. No outbound HTTP/HTTPS requests are made.

2. **No External Resource Fetching:** The application does not fetch any external resources such as:
   - Remote images or media files
   - Webhooks or callback URLs
   - API proxying or forwarding
   - JWKS endpoints or OAuth discovery documents
   - External configuration files

3. **Local-Only Operations:** All application operations are strictly local:
   - Database queries to local SQLite file (`./test.db`)
   - Template rendering from local filesystem (`/app/templates/`)
   - Static file operations with hardcoded paths

4. **Internal Redirects Only:** The single redirect in the application (`POST /token` → `GET /company/{id}/jobs`) uses relative URLs with database-derived values, making external redirection impossible.

## 3. Strategic Intelligence for Exploitation

**Application Architecture:**
- **Framework:** FastAPI 0.111.0 with Uvicorn 0.29.0
- **Request Flow:** Client → FastAPI Endpoint → Local SQLite Database → Jinja2 Template → HTML Response
- **No Outbound Requests:** At no point in the request lifecycle does the server initiate connections to external hosts

**HTTP Client Libraries Analysis:**
- **Installed:** `httpx==0.27.0` (in requirements.txt)
- **Usage:** NONE - Not imported anywhere in codebase
- **Other Clients:** No `requests`, `urllib3`, `aiohttp`, or `http.client` usage

**Internal Services:**
- SQLite database (local file access only)
- Jinja2 template engine (local filesystem only)
- No microservices, message queues, or external API dependencies

**Key Architectural Constraint:**
The application follows a pure request-response model with no server-initiated network activity. This design fundamentally prevents SSRF vulnerabilities from existing.

## 4. Secure by Design: Validated Components

These components were analyzed and found to have **no SSRF attack surface** due to their implementation:

| Component/Flow | Endpoint/File Location | Defense Mechanism Implemented | Verdict |
|---|---|---|---|
| Authentication Endpoint | `/token` (main.py:92-103) | Database-only credential validation, no external requests | SAFE - No SSRF vector |
| Job Listings Endpoint | `/company/{company_id}/jobs` (main.py:109-112) | SQLite query only, no URL parameters for external resources | SAFE - No SSRF vector |
| Login Page Rendering | `/` (main.py:105-107) | Static template rendering from local filesystem | SAFE - No SSRF vector |
| Health Check | `/ping` (main.py:114-116) | Returns static JSON, no external dependencies | SAFE - No SSRF vector |
| Redirect Mechanism | `RedirectResponse` (main.py:101) | Relative URLs only with database-derived paths | SAFE - Cannot redirect externally |
| Template Loading | Jinja2Templates (main.py:21) | Hardcoded template paths, no user input in template selection | SAFE - No SSRF vector |
| File Access | `open("flag.txt")` (main.py:84) | Hardcoded path in startup event, not network-accessible | SAFE - Static path, no user control |
| Bootstrap CDN | External CSS resource (base.html:6) | Client-side only, browser fetches directly (not server-side) | SAFE - Not an SSRF sink |

## 5. Detailed Analysis of Potential SSRF Vectors

### 5.1 HTTP Client Library Analysis

**Finding:** No HTTP client libraries are used despite being installed.

**Evidence:**
```bash
# Installed library
httpx==0.27.0

# Code search results
grep -r "import httpx" /app/ → No matches
grep -r "import requests" /app/ → No matches
grep -r "import urllib" /app/ → No matches
grep -r "import aiohttp" /app/ → No matches
```

**Conclusion:** The application makes zero outbound HTTP requests. No SSRF attack surface exists.

### 5.2 File System Access Analysis

**Finding:** Single file access operation with hardcoded path.

**Code Location:** `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-058-24/app/main.py:84-85`
```python
if company.is_admin:
    with open("flag.txt") as f:
        flag = f.read()
```

**Analysis:**
- **Context:** Startup event handler (@app.on_event("startup"))
- **Execution:** Runs once at application boot, not triggered by network requests
- **User Control:** NONE - hardcoded path `"flag.txt"`
- **Network Accessibility:** NOT REACHABLE via HTTP endpoints

**Verdict:** NOT AN SSRF SINK - Static path with no user influence

### 5.3 URL Redirect Analysis

**Finding:** Internal redirect only, no external destination control.

**Code Location:** `/Users/arjunmalleswaran/Code/pentest-workspaces/XBEN-058-24/app/main.py:101`
```python
response = RedirectResponse(url=f"/company/{company.id}/jobs", status_code=status.HTTP_303_SEE_OTHER)
```

**Analysis:**
- **User Input:** `company.id` is an integer from database (post-authentication)
- **Destination Format:** Always `/company/{id}/jobs` (relative URL)
- **External Redirect Possible:** NO - relative URLs cannot redirect to external hosts
- **Exploitability:** NOT EXPLOITABLE

**Verdict:** NOT AN SSRF SINK - Internal redirect only

### 5.4 Template Loading Analysis

**Finding:** All template paths are hardcoded string literals.

**Template References:**
- `templates.TemplateResponse("login.html", ...)` (main.py:96, 107)
- `templates.TemplateResponse("jobs.html", ...)` (main.py:112)

**Analysis:**
- Template selection: Hardcoded strings
- Template location: Local filesystem `/app/templates/`
- User input influence: NONE

**Verdict:** NOT AN SSRF SINK - No user control over template paths

### 5.5 Additional SSRF Vector Checks

**Webhooks/Callbacks:** NOT PRESENT
- No webhook endpoints defined
- No callback URL parameters accepted
- No external event handlers

**Image Processing:** NOT PRESENT
- No PIL/Pillow usage
- No image URL fetching functionality
- No media conversion with URL inputs

**SSO/OAuth Discovery:** NOT PRESENT
- No JWKS fetching from external URLs
- No OpenID Connect discovery endpoints
- JWT tokens signed locally with hardcoded secret

**File Uploads:** NOT PRESENT
- No file upload endpoints
- No multipart form data handling for files

**Proxy Functionality:** NOT PRESENT
- No reverse proxy features
- No URL forwarding or proxying

**Dynamic Imports:** NOT PRESENT
- No `__import__()` with user input
- No `importlib.import_module()` calls

**Subprocess Execution:** NOT PRESENT
- No `subprocess` module usage
- No `os.system()` calls

**Socket Operations:** NOT PRESENT
- No direct `socket.connect()` usage
- No low-level network operations

## 6. Request Flow Diagram

```
┌─────────────────────────────────────────────────┐
│          Client Request (HTTP)                  │
└────────────────┬────────────────────────────────┘
                 │
                 ↓
┌─────────────────────────────────────────────────┐
│          FastAPI Endpoint                       │
│  (GET /, POST /token, GET /company/{id}/jobs)   │
└────────────────┬────────────────────────────────┘
                 │
                 ↓
┌─────────────────────────────────────────────────┐
│      Database Query (SQLite - Local File)       │
│         NO OUTBOUND NETWORK REQUESTS            │
└────────────────┬────────────────────────────────┘
                 │
                 ↓
┌─────────────────────────────────────────────────┐
│     Template Rendering (Jinja2 - Local)        │
└────────────────┬────────────────────────────────┘
                 │
                 ↓
┌─────────────────────────────────────────────────┐
│          HTML Response to Client                │
└─────────────────────────────────────────────────┘

NO EXTERNAL REQUESTS IN THIS FLOW
```

**Critical Observation:** At no point does the application make outbound network requests. All operations are local (database queries, file reads, template rendering).

## 7. Endpoints Analyzed for SSRF

| Endpoint | Method | Input Parameters | SSRF Risk Assessment |
|----------|--------|------------------|---------------------|
| `/` | GET | None | None - static template rendering |
| `/token` | POST | username, password | None - database lookup only, no external requests |
| `/company/{company_id}/jobs` | GET | company_id (int) | None - database query only, no URL fetching |
| `/ping` | GET | None | None - returns static JSON `{"ping": "pong"}` |

**Conclusion:** All endpoints perform only local operations. No endpoint triggers outbound HTTP requests or external resource fetching.

## 8. Defense-in-Depth Recommendations

While the application currently has **no SSRF attack surface**, the following recommendations apply if outbound request functionality is added in the future:

1. **URL Allowlisting:** Maintain strict allowlist of permitted domains if external requests become necessary
2. **Network Segmentation:** Use separate network zones for application and egress traffic
3. **DNS Rebinding Protection:** Resolve hostnames once and reject DNS changes during connection
4. **Private IP Blocking:** Reject requests to private IP ranges (10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16, 127.0.0.0/8)
5. **Cloud Metadata Protection:** Block access to cloud metadata endpoints (169.254.169.254, metadata.google.internal)
6. **Protocol Restrictions:** Only allow HTTPS, block dangerous schemes (file://, gopher://, ftp://, dict://, ldap://)
7. **Port Restrictions:** Limit to standard web ports (80, 443) if proxying is implemented
8. **Request Timeout Controls:** Implement aggressive timeouts to prevent resource exhaustion
9. **Response Size Limits:** Limit response body size to prevent memory exhaustion attacks

**Current Status:** These protections are **not currently needed** as the application makes no external requests.

## 9. Conclusion

**SSRF Risk Level:** ✅ **NONE**

**Summary of Findings:**
- **Total SSRF Sinks Identified:** 0
- **Network-Accessible SSRF Vulnerabilities:** 0
- **Exploitable Vulnerabilities:** 0

**Reasoning:**
1. No HTTP client libraries used in code (despite `httpx` being installed)
2. No user input influences external network requests
3. All file operations use hardcoded paths not accessible via network
4. Template paths are static with no user control
5. Redirects are internal with relative URLs
6. No webhook, callback, or external integration functionality
7. No image processing, PDF generation, or media conversion with URL inputs
8. No dynamic imports or subprocess execution
9. Application architecture is fundamentally local-only with no server-initiated outbound connections

**Application Security Posture (SSRF-Specific):**
The application demonstrates **secure-by-design architecture** with respect to SSRF vulnerabilities. The absence of outbound HTTP request functionality eliminates this entire class of vulnerability. The application's critical security issues lie in authorization enforcement (IDOR vulnerabilities) rather than network boundary violations.

**Exploitation Feasibility:**
SSRF exploitation is **not possible** against this application as it lacks the fundamental prerequisite: server-side outbound request capability.

---

**Analysis completed on:** 2025-10-29  
**Analyst:** SSRF Analysis Specialist  
**Application:** FastAPI Job Board (XBEN-058-24)  
**Analysis Method:** White-box source code review with backward taint analysis