CVE-2023-3519-checker.py

################################################################################
# File: CVE-2023-3519-checker.py
# Version: 1.2
# Author: Deutsche Telekom CERT
# Organization: Deutsche Telekom Security GmbH
# License: GNU General Public License v3.0
################################################################################

import datetime
import requests
import time

requests.packages.urllib3.disable_warnings()

MAX_RETRIES = 3

print("#" * 80)
print("# CVE-2023-3519-checker.py")
print("# by Deutsche Telekom CERT")
print("# Don't use this as your only way of verification!")
print("#" * 80)
print("")

PATCHED_VERSIONS = [
    {"version": "13.0-91.13", "timestamp": "Fri, 07 Jul 2023 15:39:40 GMT"},
    {"version": "13.1-49.13", "timestamp": "Mon, 10 Jul 2023 17:41:17 GMT"},
    {"version": "13.1-49.13", "timestamp": "Mon, 10 Jul 2023 18:36:14 GMT"}
]

def get_last_modified(target_url):
    for _ in range(MAX_RETRIES):
        try:
            resp = requests.get(target_url, verify=False, allow_redirects=True)
            last_modified = datetime.datetime.strptime(resp.headers["Last-Modified"], "%a, %d %b %Y %H:%M:%S %Z")
            return resp, last_modified
        except (KeyError, requests.exceptions.RequestException):
            continue
    return None, None

with open("targets.txt", "r") as f:
    for target in f.readlines():
        target = f"https://{target.strip()}"
        resp, last_modified = get_last_modified(target)
        patched = False

        if resp is not None:
            for patch in PATCHED_VERSIONS:
                if last_modified == datetime.datetime.strptime(patch["timestamp"], "%a, %d %b %Y %H:%M:%S %Z"):
                    patched = True
            if not patched and last_modified < datetime.datetime.strptime("01 Jul 2023 00:00:00 GMT", "%d %b %Y %H:%M:%S %Z"):
                patched = "potentially vulnerable (older than 01 Jul 2023)"
            if not patched and last_modified > datetime.datetime.strptime("18 Jul 2023 13:00:00 GMT", "%d %b %Y %H:%M:%S %Z"):
                time.sleep(5) # sleep 5 seconds to get a different "Last Modified" timestamp
                resp_second_try, last_modify_second_try = get_last_modified(target) 
                if last_modified == last_modify_second_try: # if the timestamps would be different, this could indicate a reverse proxy or something that messes with the timestamp
                    patched = "Probably patched and customised (modification timestamp is newer than 18 Jul 2023 and not volatile)"
            elif not patched:
                patched = "potentially vulnerable (unknown timestamp)"
        else:
            patched = "not verifiable"
            last_modified = "N/A"

        print(f'target: {target} | last modified header: {last_modified} | patched: {patched}')