Gmail Attack Highlights Web Insecurity

A man-in-the-middle attack that relied on an unauthorized Google SSL certificate has revived concern over whether any Web communication is really secure.

A user posting to Google’s Gmail Help forum under the name “Alibo” claims to have received a warning from Google’s Chrome browser that the SSL certificate he received when visiting Gmail was a fake. A self-described resident of Iran, “Alibo” speculates that either his government or ISP, ParsOnline, presented the fake certificate to intercept his communications.

“Alibo” posted a copy of the certificate to PasteBin, and security researcher Moxie Marlinspike confirmed via Twitter that the certificate has a valid signature. That means that the person or entity using it could use it to intercept Gmail traffic via a man-in-the-middle (MITM) attack.

Google acknowledged the reported MITM attack and noted that the certificate authority (CA) issuing the certificate, DigiNotar, should not be issuing certificates for Google. The company also called attention to a Chrome security feature that blocked the attack.

“We’re pleased that the security measures in Chrome protected the user and brought this attack to the public’s attention,” a spokesperson said in an email. “While we investigate, we plan to block any sites whose certificates were signed by DigiNotar.”

Mozilla said it has issued updates to Firefox and other software that revoke trust in the DigiNotar root.

A separate post to PasteBin provides information about verifying the validity of the certificate’s signature and condemns Dignotar.nl for possibly enabling the Iranian government to intercept communications.

“This CA should receive an Internet death sentence as [its] carelessness may have resulted in deaths in Iran–this cert was issued in JULY of 2011 and it is now just a few days before SEPTEMBER,” the unattributed post said. “It is being used in the wild against real people in Iran *right* now.”

Or it was. DigiNotar issued a statement Tuesday saying that on July 19, 2011 it had detected an intrusion into its systems that had resulted in the fraudulent issuance of several public key certificate requests. The company says it conducted an audit to revoke those certificates but recently discovered at least one certificate had not been revoked. It subsequently consulted the Dutch government and revoked the fake certificate.

Full Story Via InformationWeek