Adobe Reader and Adobe Acrobat have been hit with yet another zero day vulnerability that is affecting all versions of both programs up to and including Adobe Reader and Adobe Acrobat 9.2.
The vulnerability has been disclosed to the public by Adobe’s Security Response team which wrote in a blog post that Adobe is “currently investigating this issue and assessing the risk to customers”.
Adobe itself did not reveal details about the exploit in the blog post but a post at the Shadowserver website which is run by security volunteers from around the world reveals details about the issue.
According to information posted on the website the exploit has been in the wild since at least December 11. The number of attacks have been limited and targeted so far according to the information. The experts expect the “exploit to become more wide spread in the next few weeks” with the potential to become fully public in the same timeframe.
The security researchers did not want to reveal all the information about the vulnerability but mentioned that it was found in the JavaScript function in Adobe Acrobat and Adobe Reader.
With that said we can tell you that this vulnerability is actually in a JavaScript function within Adobe Acrobat [Reader] itself. Furthermore the vulnerable JavaScript is obfuscated inside a zlib stream making universal detection and intrusion detection signatures much more difficult. On the bright side though, there are some solutions to this problem.
A temporary fix was also published on the same website.
We have said it before and we will say it again: Disable JavaScript.
Disabling JavaScript is easy. This is how it can be done in Acrobat Reader:
Click: Edit -> Preferences -> JavaScript and uncheck Enable Acrobat JavaScriptWe have not had time to fully test but enabling hardware DEP for systems that support it may also mitigate this issue.
Adobe users are encouraged to disable JavaScript as soon as possible to block their version of the program from being vulnerable.
Update: Adobe has published a security advisory for the vulnerability in Adobe Reader and Acrobat. The vulnerability is rated critical. Attackers can exploit it to casue a crash and potentially take control of the operating system.
Users are asked to either disable JavaScript in Acrobat or Reader, or to update to the most recent version of the product.