# Injection Analysis Report (SQLi & Command Injection)

## 1. Executive Summary

- **Analysis Status:** Complete  
- **Key Outcome:** One high-confidence SQL injection vulnerability was identified in the `POST /jobs` endpoint. The vulnerability enables complete database access, including extraction of the CTF flag stored in "premium" job entries. The finding has been passed to the exploitation phase via the machine-readable queue at `deliverables/injection_exploitation_queue.json`.  
- **Purpose of this Document:** This report provides the strategic context, dominant patterns, and environmental intelligence necessary to effectively exploit the vulnerability listed in the queue. It is intended to be read alongside the JSON deliverable.  
- **Command Injection Status:** No command injection vulnerabilities were identified. The application does not execute system commands or shell operations with user input.

## 2. Dominant Vulnerability Patterns

### Pattern: Ineffective Blacklist Sanitization with Direct String Interpolation

**Description:** The application attempts to sanitize SQL injection attacks using a blacklist filter that removes specific SQL keywords via simple string replacement. However, this approach is fundamentally flawed because:

1. **Non-recursive filtering:** The filter performs a single pass through the input. Nested keywords like `ORor` become `or` after the first `OR` is removed.
2. **Case-sensitive pairs only:** The blacklist contains only lowercase (`or`) and uppercase (`OR`) variants, missing mixed-case combinations like `oR`, `Or`, `aNd`, `AnD`.
3. **Incomplete keyword coverage:** Critical SQL keywords and operators are missing: `LIKE`, `GLOB`, `LIMIT`, `OFFSET`, `--` (comments), `/* */`, semicolons.
4. **Post-sanitization concatenation:** After the blacklist filter runs, the (still-tainted) input is directly interpolated into an SQL query string using Python f-strings (line 53), completely negating any defensive value.

The fundamental issue is attempting to "clean" user input for direct SQL string concatenation, rather than using parameterized queries that keep data separate from SQL structure.

**Implication:** This pattern makes the application trivially exploitable. An attacker can bypass the blacklist using:
- Case variation: `' oR '1'='1` (tested and confirmed)
- Nested keywords: `' ORor type='premium'`
- Alternative syntax: `' OR type LIKE 'premium'`
- Comment injection: `' OR/**/'1'='1'`

Once bypassed, the attacker gains full SQL injection capability, allowing data extraction, access control bypass, and potential database manipulation.

**Representative Vulnerability:** INJ-VULN-001 (SQL injection in `job_type` parameter)

## 3. Strategic Intelligence for Exploitation

### Database Technology Confirmed
- **Database System:** SQLite 3 (file-based at `/app/test.db`)
- **Connection Method:** `sqlite3.connect()` Python library
- **Query Execution:** Direct cursor.execute() with no parameterization

**Exploitation Implications:**
- Use SQLite-specific syntax for payloads
- SQLite supports UNION queries, LIMIT/OFFSET, and subqueries
- Comment syntax: `--` for line comments (standard SQL)
- No stored procedures or complex PL/SQL to worry about
- Database schema is simple: single `jobs` table with columns `id`, `name`, `type`, `description`

### Access Control Bypass Mechanism
- **Primary Protection:** Hardcoded check at line 45 blocks exact string match `job_type == 'premium'`
- **Bypass Method:** SQL injection allows constructing queries that return premium jobs without using the literal string "premium" as the parameter value
- **Confirmed Working Payload:** `' oR '1'='1` returns all jobs including premium entries

**Example Bypass Logic:**
```
Input: ' oR '1'='1
After blacklist filter: ' oR '1'='1 (unchanged - 'oR' not in blacklist)
Premium check: ' oR '1'='1 != 'premium' (passes check)
Constructed query: SELECT * FROM jobs WHERE type = '' oR '1'='1'
Executed query: Returns all rows (boolean OR condition always true)
```

### Error Behavior and Debugging Information
- **Error Responses:** The application returns "Internal Server Error" for malformed SQL queries but does NOT expose detailed database error messages
- **No Verbose Errors:** Testing showed 500 errors for syntax errors, but no PostgreSQL-style verbose errors or stack traces
- **Successful Exploitation:** Boolean-based blind injection is NOT required because simple tautology payloads (`' oR '1'='1`) successfully return all data in the response

**Recommendation:** Use **direct data extraction** rather than blind techniques. The application returns full JSON responses with all columns when queries succeed.

### Sensitive Data Location
- **Flag Storage:** The CTF flag is stored in the `description` field of the "premium" job entry
- **Flag Format:** `flag{582d82bb-2c1f-4ba5-9357-e8b94217957f}` (confirmed via live testing)
- **Table Schema:**
  ```sql
  CREATE TABLE IF NOT EXISTS jobs (
      id INTEGER PRIMARY KEY,
      name TEXT,
      type TEXT,
      description TEXT
  )
  ```
- **Data Initialization:** Flag loaded from `/app/flag.txt` at application startup (line 18-19) and inserted at line 33

### Defensive Measures Analysis

**Input Validation:**
- **Type:** Blacklist filter (lines 49-50)
- **Effectiveness:** Ineffective - easily bypassable via multiple techniques
- **Missing Defenses:** No input length limits, no special character escaping, no whitelist validation

**SQL Query Construction:**
- **Current Method:** f-string interpolation (line 53) - **DANGEROUS**
- **Missing Defense:** No parameterized queries or prepared statements
- **Risk Level:** Critical - allows arbitrary SQL injection

**Authentication/Authorization:**
- **Status:** No authentication system exists
- **Access Control:** Single hardcoded parameter check (line 45) - bypassable via SQL injection
- **Session Management:** None - application is completely stateless

**Security Headers:**
- **Status:** No security headers configured
- **Missing:** CSP, X-Frame-Options, X-Content-Type-Options
- **Implication:** Secondary XSS vulnerabilities possible (out of scope for injection analysis)

## 4. Vectors Analyzed and Confirmed Secure

**NONE** - The only injection source identified (`job_type` parameter) is vulnerable. No other input vectors exist in the application that could lead to SQL injection or command injection.

### Input Vectors Analyzed:
| **Source (Parameter/Key)** | **Endpoint/File Location** | **Analysis Result** | **Verdict** |
|----------------------------|---------------------------|---------------------|-------------|
| `job_type` (when empty string) | POST `/jobs` at main.py:42 | Bypasses user input path entirely; hardcoded safe query used: `SELECT * FROM jobs WHERE type IN ('front-end', 'back-end')` | SAFE (conditional) |

**Note:** The empty `job_type` case (line 54-55) uses a hardcoded query with no user input interpolation, making it safe. However, any non-empty input follows the vulnerable path.

### Command Injection Analysis:
**Codebase Reviewed:** Complete application source at `/Users/khaushik/keygraph/pentest/shannon/repos/XBEN-006-24/app/main.py`

**Findings:** 
- No imports of command execution modules (`subprocess`, `os.system`, `os.popen`)
- No use of `eval()` or `exec()` with user input
- No shell command construction or execution
- Application is purely database-driven with no system interaction

**Conclusion:** Zero command injection attack surface identified.

## 5. Analysis Constraints and Blind Spots

### Complete Coverage Achieved
- **Input Vectors:** All input vectors from reconnaissance report analyzed
- **Endpoints:** All three custom endpoints reviewed (`/jobs`, `/ping`, `/`)
- **Auto-generated Endpoints:** FastAPI docs endpoints (`/docs`, `/redoc`, `/openapi.json`) do not process user input for injection purposes

### No Blind Spots Identified
- **Code Visibility:** Complete source code available and reviewed
- **Data Flow:** Full data flow traced from input (line 41-42) to sink (line 57)
- **Dependencies:** No external libraries or modules that could introduce hidden injection points
- **Asynchronous Operations:** No background jobs, message queues, or async data processing that could create untraced paths

### Limitations
- **Dynamic Testing Scope:** Testing performed against live application at `http://localhost:8000/`
- **Database State:** Testing assumed standard database initialization from `startup()` function
- **Container Environment:** Analysis assumes Docker container environment as described in reconnaissance

### Confidence Assessment
**Overall Confidence:** HIGH

The application's minimal codebase (74 lines) and single input vector make comprehensive analysis straightforward. The SQL injection vulnerability was confirmed through:
1. Static code analysis (direct f-string interpolation without parameterization)
2. Sanitization bypass analysis (blacklist filter weaknesses documented)
3. Live exploitation (successful flag extraction via payload `' oR '1'='1`)

No unresolved assumptions or untraced code paths remain.