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Ubuntu Forum Security Breach
pinkstuff writes "There has been a major security breach of the Ubuntu Forums database. Every user's email address and salted password has been taken. From the forum home page: Unfortunately the attackers have gotten every user's local username, password, and email address from the Ubuntu Forums database. The passwords are not stored in plain text, they are stored as salted hashes. However, if you were using the same password as your Ubuntu Forums one on another service (such as email), you are strongly encouraged to change the password on the other service ASAP. Ubuntu One, Launchpad and other Ubuntu/Canonical services are NOT affected by the breach."
The hashes are salted. Who cares about a breach with salted hashes?
If they aren't sure of the extent of the compromise, reading salted hashes (assuming they were) might only be part of the problem. Could be they were intercepting passwords on the fly.
They use vBulletin.. the passwords are salted.. but it's just md5(salt+md5(password)). The salt is in the db, and it's just 2 md5 hashes -- NO stretching, PBKDF2, bcrypt, or anything else. It's literally one step up from plaintext. You can recover those passwords in very little time. You SHOULD assume the passwords are compromised.
http://www.vbulletin.org/forum/showthread.php?t=178091
I don't know about Ubuntu being that popular, but this story seems to be. We had this one on /. only four days ago. Editors asleep at the wheel again... :-|
How do you reverse an MD5 hash if it is not?
You try all possible inputs at a rate of 180 billion combinations per second.
For an 8 character alphanumeric with a few symbols, thats about 48 bits of entropy, which equates to 1564 seconds (26 minutes) to try every single possible input. Since you used a 128-bit hash on 48 bits of entropy, the odds are very very very good that only one single input will result in the stored MD5 hash.
Thus the attack knows precisely what the original password was in only 26 minutes, which fits the definition of "reversing" the hash in no more than 26 minutes.
"His name was James Damore."
The Ubuntu forums run on vBulletin, a proprietary solution. Nothing open-source about it.