Unknown SSL credential could imperil Firefox, Mac users

Mozilla web browsers and email programs and the Mac operating system contain a root authentication credential with unknown origins, a disturbing discovery that underscores the shaky foundation on which internet security is built.

The "RSA Security 1024 V3" certificate is a master credential that can be used to digitally validate the certificates of an unlimited number of websites and email servers. It's one of several dozen "certificate authority certificates" that by default are shipped with Mac OS X and Mozilla's Firefox browser and Thunderbird email client. It's valid from 2001 to 2026.

But according to security researchers, no one knows who issued or controls the digital credential. Certificate issuers RSA and VeriSign both say it's not theirs, though they have certificates that closely resemble the name. And recent audits of certificate authority credentials make no reference of it, according to this bug report posted to Mozilla's website for developers and a follow-up post on Google Groups.

The discovery is troubling, because the owner of the certificate authority certificate acts as a locksmith that can at will produce the digital keys used to prove a website or email server really is operated by the bank, retailer, or other trusted organization claiming ownership. The inclusion of a mysterious CA certificate into two separate organizations may simply be a clerical error. Or it could be a deliberate act of a criminal who managed to to slip it past the security teams of Mozilla and Apple.

"Either way, it's a very concerning situation," said Moxie Marlinspike, a security researcher and hacker who has long been a critic of the SSL, or secure sockets layer, certificate system. "Either an unknown attacker somewhere in the world has had unlimited access to SSL traffic for an unknown amount of time, or the people who we have entrusted with this critical piece of web infrastructure can't even keep track of their own certificates."

In a statement, Johnathan Nightingale, Mozilla's director of Firefox development, played down the significance of the discovery, saying all certificates are vetted according to this policy. But he also tacitly admitted Mozilla doesn't know who controls it.

"The RSA key here is one that's been around for some time, though, and whose corporate ownership has likely changed since its inclusion," he said. "What we know now is that neither RSA (maintainers of the similarly-named 2048 bit key) nor VeriSign (maintainers of the RSA Data Security Inc. key) currently use the root or get audits against it, which is why we're removing it."

Members of Apple's public relations team didn't respond to an email seeking comment.

Firefox users on Google Groups have proposed removing the RSA certificate from the NSS, or network security services, library that ships with Firefox. Since its owner has remained unknown for four days now, that's a good start.

But that shouldn't be where things end. Users of Firefox, Thunderbird, and OS X should call for an accounting of exactly how a CA certificate with unknown origins slipped into their wares and for an audit of all the credentials that remain in them now.