Here is an Nginx patch : if ($http_content_type ~* "multipart") { return 403; }
You can also turn of session progress in php.ini as mentionned but that does not seem to cover every cases : session.upload_progress.enabled = Off
It assumes PHP frees the upload progress data when it reloads the session. But PHP 8.4 (the one we use is 8.4.24, i don't know for other versions) calls Z_TRY_ADDREF(progress->data) to keep that data alive. The fake function call also seems to contain invalid fields.
This makes me question this particular PoC, not the official PHP security warning. I have not reproduced the exploit, so this is a concern based on reading the code, not proof that the real vulnerabilities cannot be exploited.
But anyway the CVE still exists, and the exploitation is tied to multipart, disabling it seems the best thing you can do now without shutting everything down.