Just a quick note for anyone out there that happens to be running the PHP 4.3.0 CGI on their machine - there has been a patch issued due to a security risk that was found in the CGI build.

According to the bug report: PHP contains code for preventing direct access to the CGI binary with configure option "--enable-force-cgi-redirect" and php.ini option "cgi.force_redirect". In PHP 4.3.0 there is a bug which renders these options useless.

Anyone with access to websites hosted on a web server which employs the CGI module may exploit this vulnerability to gain access to any file readable by the user under which the webserver runs. A remote attacker could also trick PHP into executing arbitrary PHP code if attacker is able to inject the code into files accessible by the CGI. This could be for example the web server access-logs.

So, if you're running version PHP 4.3.0 (especially as a CGI), you should get on over and upgrade as soon as possible...