An Indian certificate authority in the Microsoft root of trust has been caught issuing fake Google subdomain certificates that would allow nearly undetectable eavesdropping on "secure" connections to services like Google Docs.
The certificate authority, India's National Informatics Centre, is not trusted by browsers and operating systems from vendors other than Microsoft. Cryptographic certificates in the "root of trust" for your operating system and browsers are implicitly trusted, and rogue certificates can be used to eavesdrop on your communications, trick you into installing malicious software, and otherwise attack the integrity of your system.
The problem of rogue certificate authorities is an important one, and I wrote a paper for Nature with Google's Ben Laurie on "Certificate Transparency," Google's initiative to quickly detect rogue certificates in the wild and identify the bad actors who issue them.
We are not aware of any other root stores that include the India CCA certificates, thus Chrome on other operating systems, Chrome OS, Android, iOS and OS X are not affected. Additionally, Chrome on Windows would not have accepted the certificates for Google sites because of public-key pinning, although misissued certificates for other sites may exist.
We promptly alerted NIC, India CCA and Microsoft about the incident, and we blocked the misissued certificates in Chrome with a CRLSet push.
On July 3, India CCA informed us that they revoked all the NIC intermediate certificates, and another CRLSet push was performed to include that revocation.
Chrome users do not need to take any action to be protected by the CRLSet updates. We have no indication of widespread abuse and we are not suggesting that people change passwords.
Maintaining digital certificate security [Adam Langley/Google Online Security]
(via Hacker News)