Mozilla today said that it regretted staying silent when it found out last week that hackers had stolen digital certificates for some of the Web's biggest sites, including Google, Skype, Microsoft, Yahoo and its own add-on site.
On March 15, attackers used a valid username and password to obtain nine SSL certificates -- which essentially prove that a site is what it says it is -- from an Comodo certificate reseller. The certificates were for six Web sites, including the log-on sites for Microsoft's Hotmail, Google's Gmail, the Internet phone and chat service Skype, and Yahoo Mail. A certificate for Mozilla's Firefox add-on site was also acquired.
Comodo disclosed the breach of its reseller and the theft of the SSL certificates on March 23. Between March 15, when Comodo realized its reseller had been hacked, and March 23, the company revoked the certificates and contacted browser makers Mozilla, Google and Microsoft.
Although Google patched Chrome on March 17, Mozilla and Microsoft issued updates to Firefox and Windows on March 22 and March 23, respectively. Those patches added the stolen certificates to the browsers' blacklists as a fallback defense in case users reached fake sites secured with the certificates.
Comodo said evidence pointed to Iranian government involvement in the attack and theft, and speculated that the certificates were stolen to set up fake sites where authorities could identify activists and monitor their e-mail and other digital communications.
None of the browser makers went public with the Comodo hack or the existence of the rogue certificates before March 22.
"Mozilla did not publish the information we received prior to shipping a patch," the company acknowledged in a Friday entry on its security blog. "In early discussions, we were concerned that any indication that we knew about the attack would lead to attackers blocking our security updates as well."
Today, Mozilla said that that was a mistake.
"In hindsight, while it was made in good faith, this was the wrong decision. We should have informed Web users more quickly about the threat and the potential mitigations as well as their side-effects," said Mozilla.
Jacob Appelbaum, a researcher at the University of Washington's Security and Privacy Research Lab who independently uncovered the certificate theft, had urged Mozilla developers to warn users rather than wait to ship a blacklist update, even if that meant ignoring Comodo's request that everyone stay in sync and not disclose the theft until March 23.
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