Adobe on Monday released an update to fix a critical vulnerability its Reader and Acrobat software that could affect people running Microsoft Windows XP and Internet Explorer 7.

The vulnerability could allow an attacker to take control of the computer running the affected Adobe software. It was first disclosed September 20th and confirmed by Adobe on October 5th.

"A malicious file must be loaded in Adobe Reader or Acrobat by the end user for an attacker to exploit these vulnerabilities," Adobe said. "This issue is remotely exploitable."

A video showing the vulnerability being exploited can be found on YouTube.

The vulnerability affects Adobe Reader 8.1 and earlier, Adobe Reader 7.0.9 and earlier, Adobe Acrobat Professional, 3D and Standard 8.1 and earlier, Adobe Acrobat Professional, Standard, 3D and Elements 7.0.9 and earlier.

Adobe recommends that users upgrade to Adobe Reader 8.1.1 or Acrobat 8.1.1.

Adobe plans to deliver updates to Adobe Reader 7.0.9 and Acrobat 7.0.9 at a later date. In the meantime, IT administrators may choose to disable the mailto: option in Acrobat, Acrobat 3D and Adobe Reader by changing the application options in the Windows registry.

Microsoft issued a related security advisory on October 10th.

This is not the first fix Adobe has issued for Windows-based systems since the beginning of the year. A vulnerability exposed in January stems from Adobe Reader's "Open Parameters" feature that lets developers pass parameters when opening a PDF file. Adobe also spent considerable time and effort getting its software to interoperate with Windows Vista.