You need to update if you use:
Microsoft WindowsThe current version of Adobe Reader is 9.x. If you update to that version this security risk will also be solved. Adobe Reader is FREE from http://adobe.com
Adobe Reader Version 8.x
CRITICAL SECURITY ALERT – Update Your Adobe Reader’s
There’s a critical, remotely exploitable vulnerability in Adobe Acrobat/Reader version 8. This effects Adobe Acrobat reader installed on Windows platform.
According to a recent report by Core Security, Adobe Reader is said to have a critical bug that could allow manipulated PDF’s to be sent and then after opening the user could be exploited via the rigged file.
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