Adobe pulls mobile Flash, but with no 'kill switch' security concerns remain

It was not breaking news that Adobe pulled its Flash Player plugin from Google's Android marketplace Play on Wednesday. The company had announced last November that it was ending development of the multimedia playback software for mobile devices.

Still, it was an event worth noting by numerous news outlets, partially because it marks the end of what had been promoted as advantage of Android devices over those using Apple's iOS.

It does, however, have security implications in a BYOD (Bring Your Own Device) world where even state-of-the-art perimeter security is useless if an endpoint device with access is compromised.

Adobe has had a history of security problems. Ed Bott, writing on ZDNet in May 2010, complained of "a steady stream of denial where there should be transparency." He cited a 2009 study by Symantec that found 23 vulnerabilities in Flash Player.

Steve Jobs, the late founder of Apple, had criticized Flash in an open letter in April 2010, explaining why Apple was not allowing Flash on iPhones, iPods and iPads. Among his criticisms: That it was not an open system, was too much of a drain on the batteries of mobile devices, did not perform well with multi-touch operation and its performance, reliability and security were all poor.

[Bill Brenner in Salted Hash: Adobe releases its own Patch Tuesday security updates]

In short, Jobs wrote, Flash was a "relic" of the PC era and should yield to newer, open standards for the mobile era such as HTML5, CSS and JavaScript.

And even though Adobe became much more aggressive about issuing patches, it eventually agreed with Jobs about HTML5. Danny Winoker, vice president and general manager of interactive development for Adobe announced in a November 2011 blog post that HTML5 is now the "best solution for creating and deploying content in the browser across mobile platforms."

"We are excited about this, and will continue our work with key players in the HTML community, including Google, Apple, Microsoft and RIM, to drive HTML5 innovation they can use to advance their mobile browsers," Winoker wrote.

And Mike Chambers, Adobe's principal product manager for developer relations, wrote in a separate post that the company would focus on enabling Flash developers to package native apps with Adobe AIR, an HTML5-based solution, for all the major app stores.

Does this then offer some relief to IT managers trying to protect enterprise data in a BYOD world? Expert opinions are mixed.

Not really, per Chris Larsen, chief malware researcher at Blue Coat, who says he doesn't think Flash has been a major threat for mobile users. "Most of the Android malware we've seen uses social engineering to convince the victim to install an app, not a drive-by download courtesy of a Flash vulnerability," he said.

Larsen said Adobe's difficulty in producing a reliable version of Flash for all iterations of Android phones may have made it "more difficult for the bad guys to weaponize a vulnerability in Android Flash into a reliable exploit that works on all, or even most, of the phones."

"It's a case where the instability of Flash protected users," Larsen said.

But what security flaws there are will not be going away immediately, said Zach Lanier, a security researcher and expert in mobile security. "Although Flash -- which, as we know, has been plagued by security issues -- is effectively going away from Android, taking with it a potential attack surface, there's still the question of exposure between the end of support and security updates and when Flash completely disappears from Android," he said.

"Although it's being pulled from Google Play, meaning no new downloads, unless users actually heed Adobe's advice and manually remove Flash, or the 'kill switch' is activated, removing the runtime from affected devices, or an OTA update removes Flash, there will still be a respectable number of Android devices with Flash installed and enabled," Lanier said.

Regarding BYOD risks: "Without an enforceable policy limiting or outright denying Flash installations on enterprise-connected Android devices, it's sort of moot," he said.

Read more about wireless/mobile security in CSOonline's Wireless/Mobile Security section.

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