Flash Player 11: Adobe's great security hope

But we can still blame the lazy users for successful PDF attacks

Flash Player 11 should fix plenty of security holes, just like Adobe Reader X did a year ago. But Adobe's products will continue to be a target as long as people insist on running obsolete software.

Adobe must be getting used to this by now. Their PDF document format has been the tool of choice for hackers wanting to deliver malicious payloads into organisations large and small for more than a year -- certainly since last year's Operation Aurora attacks against Google, Juniper Networks, Rackspace, Adobe themselves and the other, unnamed, victims.

Yet the software flaw that allowed this to happen was fixed in Adobe Reader and Acrobat version X, released in November 2010.

"In 2011, we haven't seen any malicious PDFs that go after Reader proper," said Brad Arkin, Adobe's head of product security and privacy. "We have seen two examples of malicious PDFs which encapsulated malicious SWF [Flash] content."

"Thus far, no bad guys have successfully deployed any malware that's effective against version X," he told CSO Online.

But these attacks continue to succeed because most people are still using out-of-date versions of Adobe Reader.

"It's exclusively a situation where users of older versions are being targeted," Arkin said. "We've studied this problem quite a bit because it is the biggest obstacle for us to help our users stay safe."

In April 2010, Adobe introduced a silent automatic mode for updating Reader and Acrobat without the user having to interrupt their work. Even though it wasn't the default setting, Arkin said that enough users adopted it to reduce the time to roll updates out to the user base by about 70 percent.

In June this year, the silent automatic mode became the default. Adobe's 13 September update was the first to be distributed under this new regime. While the numbers aren't in yet, Adobe's goal is that "most of the users in that consumer environment will get the updates within maybe 72 hours of when we ship it, and it'll be effortless from the user perspective."

The bad guys had originally started attacking Adobe Reader because Microsoft had been gradually improving the security of Windows. And now, as Adobe fixes Reader and Acrobat, the bad guys move again.

"The threat landscape out there has shifted, where instead of going after Adobe Reader X, we have seen people go after other Adobe products, and so things that are very widely deployed," Arkin said.

Things like Flash Player.

A zero-day exploit against the widely-deployed browser plugin forced Adobe to issue an urgent fix last month. Just like another one did in April. Twice. More attacks will doubtless follow.

The Flashback Mac Trojan posed as a Flash updater, trading off Adobe's good name while it installed a back door in OS X.

Adobe hopes that this month's release of Flash Player 11 will help.

Flash Player 11's security improvements include:

* Random numbers now come from the host operating system's random number generator, which might include cryptographic-quality hardware random number generators, rather than Flash's built-in game-quality code.

* Encrypted SSL/TLS connections now go directly from Flash Player to the remote server, rather than using SSL over HTTP in the browser, cutting down on the processing overhead.

Flash Player 11 also provides access to the computer's graphics processing unit (GPU) for gaming and other computationally-intensive applications, but Adobe downplays the risk of this direct hardware acces allowing a malicious Flash application to write to the screen.

"Security guys are taught to worry, so you're never worrying about nothing," Arkin said, "[but] there's a lot in between the ActionScript the developer writes and the actual GPU hardware access."

"We don't see that really changing the attack vectors that bad guys and going to use, because the access to the hardware is abstracted so much," he said. "We've spent a lot of effort to make sure the bad guys can't do anything interesting with it."

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Contact Stilgherrian at Stil@stilgherrian.com or follow him on Twitter at @stilgherrian

Tags adobetrojanadobe flashOS XAdobe Reader XFlash Player 11Operation Aurora attackszero-day exploitmalicious PDFs

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