Mandriva Linux Security Advisory 2009-066 – PHP 4.4.4, 5.1.6, and other versions, when running on Apache, allows local users to modify behavior of other sites hosted on the same web server by modifying the mbstring.func_overload setting within.htaccess, which causes this setting to be applied to other virtual hosts on the same server. The updated packages have been patched to correct these issues.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/75445/MDVSA-2009-066.txt
Source: https://packetstormsecurity.com/files/75445/Mandriva-Linux-Security-Advisory-2009-066.html