The delay in disclosing a theft of the digital certificates for some of the Web's biggest sites, including Google, Skype, Microsoft and Yahoo, put Iranian activists' lives at risk, a researcher argued Wednesday.
Comodo, the Jersey City, NJ-based security company whose reseller issued the bogus certificates, disputed the charge, saying that at no time was anyone at risk.
Last week, attackers used a valid username and password to obtain nine SSL certificates -- used to prove that a site is legitimate -- from an Comodo affiliate. 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.
At least one of the certificates, for logon.yahoo.com, was used to legitimize a fake Yahoo site hosted by an Iranian ISP (Internet service provider), Comodo said yesterday.
Comodo's CEO and founder, Melih Abdulhayoglu, said there was evidence, largely circumstantial, that the Iranian government had backed the hack of its partner to obtain SSL certificates.
"I'm betting on Iran," said Abdulhayoglu, who said that the original attack on its reseller originated from that country. "It was too well executed for cybercriminals. It was very well planned, and they knew exactly what to get."
If that was the case, then Iranian authorities could have manipulated the country's DNS infrastructure -- the Internet's traffic routing mechanism -- to divert any Iranian users trying to reach, say, Yahoo Mail, to a fake version secured by the stolen certificate. When an Iranian logged into his Yahoo Mail account, he would have then unknowingly given his username and password to authorities, who in turn could use those credentials to read his e-mail.
Comodo waited eight days before disclosing the attack, using that time to investigate, revoke the certificates and contact browser makers such as Google, Mozilla and Microsoft so that they could issue updates to block the bogus certificates.
That delay put Iranians at risk, said Jacob Appelbaum, a researcher at the University of Washington's Security and Privacy Research Lab. Appelbaum independently uncovered the theft of the certificates last week, and contacted Comodo, Mozilla and Google with his findings.
On Tuesday, Appelbaum published his analysis on the Tor Project's blog. Tor is a system that lets people connect to the Web anonymously, and is often used in countries where governments monitor their citizens' online activities.
"By keeping this quiet for eight days, Comodo and others put lives at risk," said Appelbaum, referring to Iranian anti-government activists who may have been redirected to fake sites and thus revealed their identities and plans. "They were completely unable to protect themselves during that time. Users should have had this information sooner."
Appelbaum said that Iranian authorities confront activists with online evidence of their alleged crimes during interrogations. "They regularly show those who are arrested data on their Internet traffic," said Appelbaum.
Abdulhayoglu said there was no proof that anyone in Iran was at risk because of the disclosure delay.
The only certificate that Comodo saw actually in use was one of the three assigned to Yahoo, login.yahoo.com. "Only one certificate was seen live, and that was just a test," said Abdulhayoglu.
According to Comodo, the fake Yahoo site went offline shortly after the company revoked the phony certificate.
Comodo has not been able to confirm if the attackers were actually able to obtain any of the other eight certificates before they were revoked, Abdulhayoglu admitted. He also declined to share details of the attack, including the reseller whose account was used to acquire the certificates or how the hackers obtained the reseller's username and password, citing ongoing law enforcement investigations.
In any case, there was no reason to disclose the theft before browser makers could patch their software to block the stolen certificates. "There's no point in disclosing unless there's a remedy," Abdulhayoglu said. "Hence the patches, which make everyone secure."
Several times Abdulhayoglu said the delay was necessary for "responsible disclosure," the practice of withholding information about security vulnerabilities or problems until a fix is ready.
Google, Microsoft and Mozilla have each issued updates that add the nine stolen certificates to their browsers' blacklists.
But Appelbaum argued that no one -- other than the attacker who had the stolen certificates -- would have been harmed if Comodo and others had broken the news earlier.
"The only people that can attack using [the certificates] are those who have them," said Appelbaum. "I can't launch an attack, I am only able to detect an attacker using [the certificates]."
Gregg Keizer covers Microsoft, security issues, Apple, Web browsers and general technology breaking news for Computerworld. Follow Gregg on Twitter at @gkeizer , or subscribe to Gregg's RSS feed . His e-mail address is firstname.lastname@example.org.
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