From Chris Karakas "Hello Nukers,

I have been informed by waraxe that the PHP Manual, PEAR manual and PHP-Nuke HOWTO modules for PHP-Nuke have a serious security vulnerability. I have checked it and it is indeed so. I have made available new, corrected versions in

PHP Manual module for PHP-Nuke
PEAR Manual module for PHP-Nuke
PHP-Nuke HOWTO module for PHP-Nuke

In case you have one of these installed on your site, please upgrade as soon as possible - you also get the newest manuals as a reward. ;-) "