Adobe to beef up PDF security with Reader sandboxing

Computerworld - Adobe Systems Inc. today announced that it will harden the next version of its popular Reader PDF viewer, a frequent target of attacks, by adding "sandboxing" technology to the software.

Sandboxing, perhaps best known for its use in Google Inc.'s Chrome browser, isolates processes from one another and the rest of the machine, preventing or hindering malicious code from escaping an application to wreak havoc or infect the computer.

Previously, security experts had said that sandboxing Reader would be a smart move by Adobe as it struggled to lock down the program and prevent vulnerabilities from being exploited by hackers.

According to Brad Arkin, Adobe's director of security and privacy, sandboxing will be added to the next major Windows upgrade to Reader, Version 10, before the end of the year. The company declined to provide a more specific timeline.

"With sandboxing, anyone who encounters a malicious PDF will find that a successful exploit is kept within the sandbox," said Arkin, describing the advantages of the technology, which is also used by Microsoft's Internet Explorer 7 and IE8, as well as by Office 2010. Although attacks may still succeed, they would require a second exploit, one that allows the attacker to move malware outside the sandbox, to be effective.

The Reader browser plug-in already makes use of IE7's and IE8's Protected Mode -- the name for sandboxing in Microsoft's browser -- as well as Chrome's isolation functionality, but the addition to Reader in general will also protect Firefox users from attack, as well as people who run the stand-alone version of the PDF viewer.

Initially, Reader will sandbox only "write" calls by the program -- blocking attempts by malware to install malicious code on the system -- but a minor release in the future will extend the technology to read-only activities, such as those aimed at pillaging the PC of important information, such as credit card numbers or passwords.

"In the first release, everything that is involved in rendering a PDF has to happen within the sandbox," said Arkin, noting that that includes parsing the PDF document and any associated images, and running JavaScript. The latter has been an especially attractive method of exploiting Reader vulnerabilities.

The technology, which will be switched on by default, will be tagged as Protected Mode, the same term used by Microsoft in IE7 and IE8.

Adobe did more than borrow the label from Microsoft. "Microsoft and Google offered a lot of advice," acknowledged Arkin, who said that Adobe based its technology on techniques described in 2007 by David LeBlanc, a Microsoft secure code expert, and with fellow Microsoft developer Michael Howard, co-author of Writing Secure Code.