According to https://www.php.net/manual/en/security.cgi-bin.force-redirect.php, the configuration directive cgi.forceredirect prevents anyone from calling PHP directly with a URL like http://host.example/cgi-bin/php/secretdir/script.php. The default value of cgi.forceredirect is 1.

But there is a bug that can cause attackers to bypass restrictions and access php-cgi directly.

It was reported that php-fpm package is vulnerable to symlink attack:

ls -lad /var/log/php-fpm drwxrwx--- 2 apache root 4096 May 28 18:53 /var/log/php-fpm

https://git.centos.org/blob/rpms!php/4b401fd4915cda3a1a336902afad4e5321859c32/SPECS!php.spec#L1409

%attr(770,apache,root) %dir %{localstatedir}/log/php-fpm

After installing php-fpm package, any software running under apache user can create symlink /var/log/php-fpm/error.log pointing to any file. After starting php-fpm service - file pointed by symlink will be appended by php-fpm log output. If a file did not exist before - it will be created. This issue only exist for a short time - after php-fpm package install and before php-fpm process is started for the first time. Exiting working configurations are not affected by this issue.

Steps to reproduce: - make sure you don't have php-fpm leftovers: # rm -rf /var/log/php-fpm - install php-fpm: # dnf install php-fpm - as an 'apache' user create an evil symlink: # su -s /bin/bash - apache $ ln -s /root/.bashrc /var/log/php-fpm/error.log - start php-fpm process: # systemctl start php-fpm - look at the contents of /root/.bashrc file (php-fpm error log output will be appended there) # cat /root/.bashrc

Erroneous parsing of multipart form data

Fixed bug (Logs from childrens may be altered). (CVE-2024-9026)