A recent vBulletin 4 (all versions, Suite & Classic) report indicated that if an installation had been hacked previously, the attacker could hide malicious code to allow a repeated attack. To further strengthen vBulletin?s security - additional security checking and query cleaning were added to thwart such attacks.
The issue does not affect vBulletin 3.x.
To improve the security of your vBulletin 4 installation please download the patch from the members area of vBulletin:
http://members.vbulletin.com/
We recommend you install this security patch as soon as possible.
The upgrade process is the same as previous patch level releases - simply download the patch from the Members' Area, extract the files and upload to your webserver, overwriting the existing files. There is no upgrade script required.
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