Adobe Systems Inc. has released updates to fix a critical zero-day flaw in its widely-used programs for making and reading .pdf documents. Attackers could exploit the flaw to hijack machines running Windows XP with Internet Explorer 7.
The flaw affects Adobe Reader and Adobe Acrobat Standard, Professional and Elements 8.1 and earlier versions, and Adobe Acrobat 3D. Adobe recommended that affected users update to Adobe Reader 8.1.1 or Acrobat 8.1.1.In an advisory Monday Adobe said that the flaw only affects customers using Windows XP with Internet Explorer 7 installed. The user must upload a malicious file in Adobe Reader or Acrobat for a successful attack to occur.
In addition to the latest update, Adobe said it plans to update Adobe Reader 7.0.9 and Acrobat 7.0.9. For customers who can't upgrade to Adobe Reader 8.1.1 or Acrobat 8.1.1, the vendor suggested disabling the "mailto:" option in Acrobat, Acrobat 3D and Adobe Reader by modifying the application options in the Windows registry. The changes can also be added to network deployments to Windows systems, Adobe said.
Millions of people use Adobe Acrobat to create .pdf documents and Adobe Reader to view them. Researcher Petko D. Petkov first disclosed the security hole Sept. 20, writing in the GNUCitizen blog that "the issue is quite critical given the fact that .pdf documents are in the core of today's modern business. This and the fact that it may take a while for Adobe to fix their closed-source product are the reasons why I am not going to publish any POCs (proof-of-concept code)."
This isn't the first time Adobe users have faced a serious security threat. In January, security experts were rattled by the disclosure of easily-exploitable Adobe Reader flaws that could be used for cross-site scripting attacks and other mayhem.