GitHub has revoked an unknown number of cryptographic keys used to access accounts after a developer found they contained a catastrophic weakness that came to light some seven years ago.
The keys, which allow authorized users to log into public repository accounts belonging to the likes of Spotify, Yandex, and UK government developers, were generated using a buggy pseudo random number generator originally contained in the Debian distribution of Linux. During a 20-month span from 2006 to 2008, the pool of numbers available was so small that it made cracking the secret keys trivial. Almost seven years after Debian maintainers patched the bug and implored users to revoke old keys and regenerate new ones, London-based developer Ben Cartwright-Cox said he discovered the weakness still resided in a statistically significant number of keys used to gain secure shell (SSH) access to GitHub accounts.
"If you have just/as of late gotten an email about your keys being revoked, this is because of me, and if you have, you should really go through and make sure that no one has done anything terrible to you, since you have opened yourself to people doing very mean things to you for what is most likely a very long time," Cartwright-Cox wrote in a blog post published Monday. "It would be safe to assume that due to the low barrier of entry for this, that the users that have bad keys in their accounts should be assumed to be compromised and anything that allowed that key entry may have been hit by an attacker."