Mitigate the Adobe Zero-Day Vulnerability While Waiting for a Patch

It's no secret there is a zero-day flaw affecting Adobe Reader and Acrobat. A solution, however, has been more elusive.

According to Secunia, the vulnerability affects versions 9 and earlier and is due specifically to an array indexing error in the processing of JBIG2 streams. The situation can be exploited to corrupt arbitrary memory via a specially crafted PDF file.

With attacks ongoing, Adobe Systems has issued an updated advisory and security companies have offered up some advice of their own for dodging exploits circulating the Web. Here is some of the latest information about how to protect your computer.

- Disable JavaScript in Adobe Reader: Security pros recommend that users consider disabling JavaScript. However, this will only work against some exploits and does not resolve the underlying issue.

- Set your browser to not automatically open PDFs: The current versions of Internet Explorer and Mozilla Firefox automatically open PDFs by default.

"If you were to go to a compromised Web site that is trying to infect you with malicious PDFs, you're going to be infected, unless your AV catches it," noted Roel Schouwenberg, senior anti-virus researcher at Kaspersky Lab Americas.

- Be wary of PDF files from unknown or untrusted sources: This should go largely without saying, but users should avoid opening up PDF files if they are suspicious.

- Consider enabling DEP (Data Execution Prevention) for Adobe Reader.

- Maintain up-to-date anti-virus protections: Many of the larger security vendors such as Symantec and McAfee offer some sort of generic protection against the flaw.

In addition to these, Sourcefire has created a homemade patch to serve as a band-aid until Adobe releases a fix for the issue. The Sourcefire patch can be downloaded here.

Officials at Adobe plan to make an update for Adobe Reader 9 and Acrobat 9 available by March 11. In addition, Adobe is planning to make updates available for Adobe Reader 7 and 8 and Acrobat 7 and 8 by March 18.