Security

DigiNotar Certificates Are Pulled, but Not on Smartphones

Browser makers have generally been quick to react to the computer compromise at digital certificate issuer DigiNotar, but that hasn't been the case for all mobile phone makers.

On Tuesday neither Google nor Apple would comment on whether they plan to revoke certificates issued by DigiNotar for Android or the iPhone, even as desktop software makers pulled the plug on the Dutch company's certificates.

Apple hasn't said anything about the DigiNotar situation since it was disclosed last week, but Google was quick to revoke the company's certificates for its Chrome browser last week. Its silence Tuesday spoke to the complexity of its situation as both a victim of the attacks and a provider of the software that can thwart them. The problem is that Google's Android phones are updated via mobile phone carriers, companies that are typically much slower to issue patches than PC software vendors such as Microsoft.

Google needs to work carefully with carriers before they can push out patches, said Marsh Ray, a senior software engineer with online authentication vendor PhoneFactor. "What if the carrier's only payment method is a Web page using a certificate signed by DigiNotar?" he said in an instant message interview. "It would be disaster if Google pushed such an update blindly."

Developers on the unofficial community Android distribution, Cyanogenmod, expressed similar reservations in their discussion forum. Worried about the possible fallout, they were initially reluctant to push out an update that revoked DigiNotar's certificates, but they changed their mind as the seriousness of the situation became clear.

Apple issues its patches directly to iPhone users, but it too must be sure to keep its carrier partners happy.

The lack of patches raises questions for mobile phone users in Iran, who may not be able to tell who they should trust on the Internet. Iranian users were the target of the DigiNotar hack, and as many as 300,000 of them have been directed to fake websites that used the bogus certificates, forensic auditors investigating the incident reported Monday.

The digital break-in seems to have been a data-gathering expedition, designed to steal Gmail messages and other information.

In fact, the hackers who broke into DigiNotar issued hundreds of digital certificates, including one for Google.com, which allowed them to take a first step in tricking Internet users into believing that one of their servers actually belonged to Google. The second step is to take control of the network's Domain Name System (DNS) and direct users to the fake site whenever they type in the Google.com address.

Microsoft's Windows Phone software does not include DigiNotar in its list of trusted certificate authorities and that appears to be the case on at least some BlackBerry phones as well. As was the case with their smart-phone competitors, neither Microsoft nor Research In Motion could answer questions on this topic Tuesday.

Roel Schouwenberg, a security researcher with antivirus vendor Kaspersky Lab is distrurbed by Google's silence, in particular, on the matter, because Google was one of the first companies to patch its Web browser. "The fact that google on the one hand has been very proactive while at the same time keeping radio silence about any update for Android is very worrisome," he said.

He said that the fact that Google must rely on mobile carriers to push out its patches could become a bigger problem as more attacks against phones surface. "Can you imagine if HP or Dell laptops received Windows updates one or two months after they were published for the general public?"

Robert McMillan covers computer security and general technology breaking news for The IDG News Service. Follow Robert on Twitter at @bobmcmillan. Robert's e-mail address is robert_mcmillan@idg.com

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