Pure memory corruption path: OOM during multipart parsing leaves stale
BG(serialize) state in Apache mod_php prefork workers. Heap spray
reclaims the freed 64-byte slot, giving control of a HashTable's
pDestructor for arbitrary function call.
No LFI, no framework, no non-default PHP settings required.
Tested on PHP 8.3.6 + Apache 2.4.58 (prefork MPM). Confirmed:
- OOM via field flood, worker survival, session file persistence
- Stale BG(serialize).level across requests
- Heap spray targeting ZendMM 64-byte bin
New exploit at fcgi/exploit_fcgi.py combines the session upload progress
write primitive (CVE-2026-109618/109619) with direct FastCGI access to
PHP-FPM. A slow-drip multipart upload holds one FPM worker in the
multipart parser while a second FastCGI request includes the poisoned
session file via auto_prepend_file.
Works on default PHP configuration, no LFI, no framework, no libraries.
security.limit_extensions does not block auto_prepend_file inclusion.
php_admin_value in pool config does not block PHP_VALUE from raw FastCGI.
Tested and confirmed RCE on:
PHP 8.3.6 (local, pre-patch)
PHP 8.3.35 (Docker, pre-patch)
PHP 8.3.36 (Docker, patched)
PHP 8.4.27 (Docker, patched)
Mitigated by session.upload_progress.enabled=0 or blocking FPM access.
Also includes nolfi/ exploit (served save_path + pathinfo routing) from
previous work, and updated README with mitigation matrix for all vectors.
Exploits the interaction between php_serialize and php session handlers:
when one endpoint writes sessions with php_serialize (Laravel, Symfony
default) and another reads with the php handler (PHP default), injected
pipe characters cause arbitrary deserialization at session_start().
12 built-in POP chains covering current and legacy library versions:
- monolog3-fw: Monolog 3.0+ (tested 3.12.1, latest)
- laravel10-cmd/fw: illuminate 10.0-13.x+ (tested v13.38.0, latest)
- monolog-cmd/fw: Monolog 1.17.2-2.x
- laravel-cmd/fw: illuminate 5.4-8.x
- guzzle-fw: Guzzle 4.0-7.x
- symfony-cmd/fw: Symfony 2.6-4.4.18
- wordpress-cmd/fw: WordPress 6.4.0-6.4.1
All chains tested end-to-end through the full HTTP exploit flow on
PHP 8.3. Accepts custom phpggc chains via --chain-file.
neko