Buffer consumption vulnerability in the tempnam function in PHP 5.1.4 and 4.x before 4.4.3 allows local users to bypass restrictions and create PHP files with fixed names in other directories via a pathname argument longer than MAXPATHLEN, which prevents a unique string from being appended to the filename.
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.