There is a remote exploit in the wild for PHP 5.4.3 in Windows, which takes advantage of a vulnerability in the com_print_typeinfo function. The php engine needs to execute the malicious code, which can include any shellcode like the the ones that bind a shell to a port.

Since there is no patch available for this vulnerability yet, you might want to do the following:

• Block any file upload function in your php applications to avoid risks of exploit code execution.
• Use your IPS to filter known shellcodes like the ones included in metasploit.
• Keep PHP in the current available version, so you can know that you are not a possible target for any other vulnerability like CVE-2012-2336 registered at the beginning of the month.
• Use your HIPS to block any possible buffer overflow in your system.

Manuel Humberto Santander Peláez
SANS Internet Storm Center - Handler
Twitter:@manuelsantander
Web:http://manuel.santander.name
e-mail: msantand at isc dot sans dot org