Standalone PHP CGI scripts could be made to execute arbitrary code with the privilege of the web server.
It was discovered that PHP, when used as a stand alone CGI processor for the Apache Web Server, did not properly parse and filter query strings. This could allow a remote attacker to execute arbitrary code running with the privilege of the web server. Configurations using mod_php5 and FastCGI were not vulnerable.
4 May 2012
A security issue affects these releases of Ubuntu and its derivatives:
Standalone PHP CGI scripts could be made to execute arbitrary code with the privilege of the web server.
It was discovered that PHP, when used as a stand alone CGI processor for the Apache Web Server, did not properly parse and filter query strings. This could allow a remote attacker to execute arbitrary code running with the privilege of the web server. Configurations using mod_php5 and FastCGI were not vulnerable.
This update addresses the issue when the PHP CGI interpreter is configured using mod_cgi and mod_actions as described in /usr/share/doc/php5-cgi/README.Debian.gz; however, if an alternate configuration is used to enable PHP CGI processing, it should be reviewed to ensure that command line arguments cannot be passed to the PHP interpreter. Please see CVE-2012-2311 for more details and potential mitigation approaches.
The problem can be corrected by updating your system to the following package versions:
To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.
In general, a standard system update will make all the necessary changes.
Vulmon