This is the most important information for popular WordPress bloggers to keep their blog safe from the hackers. Recently vulnerability has been discovered in TimThumb which used for image resizer in most of WordPress Themes and plugins. You should take action before your blog or website get hacked, because author of timthumb also confirmed about this.
How TimThumb affect or can be fixed?
Its allows attackers to upload and execute arbitrary PHP in cache directory of timthumb as result hackers can run your blog on their fingertips. If you want to fix this issue you need to delete timthumb.php or thumb from your control panel which can be found here wp-content>>Themes>>YourCurrentTheme you can replace your timthumb.php file with latest update http://code.google.com/p/timthumb/
Do not upgrade your WordPress to 3.2.1
If you are getting notification about WordPress update 3.2.1 is available and you need to update your blog, we recommend you think before you click on upgrade now link. Please take complete backup of your blog before making any major changes or installing any plugins.