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A theoretical question. There seems to be some question about whether any passwords were actually leaked, but in principle some password data could have gotten

by _kst_ 10y ago

A theoretical question. There seems to be some question about whether any passwords were actually leaked, but in principle some password data could have gotten out. What would actually have been leaked, a cleartext password or the encrypted/hashed password stored on an affected server (or both)? I have accounts on a number of sites that were affected by Cloudbleed, as indicated by http://www.doesitusecloudflare.com/ http://www.doesitusecloudflare.com/, and I've already changed my passwords on those sites. But the passwords I use are randomly generated and should be practically unguessable given a hashed version. Would I have been at risk if I had left my passwords alone?

PuffinBlue 10y ago
I forced user password resets on a forum I run. It is powered by myBB. This is towards the edge of my knowledge circle but... It doesn't appear that any hashing takes place client side[0] with myBB before the password is transmitted to the server, but I may have missed it when rechecking the code. Presumably that would mean in my case users who logged in potentially had their cleartext passwords pass through Cloudflare's network when they submitted their login details. Despite being behind https, when https is terminated at Cloudflare's edge and re-encrypted to my origin server (I use full/strict crypto setting), there was the possibility for decrypted data to be held in memory and then the possibility for it to be injected into the html pages of other sites when the bug was triggered. It would be a very very small probability of actually happening, but not zero. No details from the server should have leaked because only the content of transmitted data that passed over Cloudflare could have been leaked and the comparison of the provided password to the hashed/salted one in the database would have occurred on the server and not passed over the network. So the answer is it would depend on the way the sites you use handled password transmission and comparison. Personally I'd change them, and actually have done so for sites I use. [0] https://community.mybb.com/archive/index.php?thread-88668.html https://community.mybb.com/archive/index.php?thread-88668.ht...
orthecreedence 10y ago
> What would actually have been leaked, a cleartext password or the encrypted/hashed password stored on an affected server (or both)? Depends on the app. The apps I write will do a PBKDF2 w/ 20K rounds on a password before sending to the server, which then hashes that hash again before storing/comparing. I suspect most apps just sent the username/password plaintext over SSL, meaning the plaintext passwords would have been leaked if the app used Cloudflare to terminate SSL. That said, if someone got the PBKDF2ed password hash from the SSL payload, they could just as easily use that to log into an account, but they'd have to at least do a little bit of work to break the hash if they wanted to actually crack the password. In other words, you were absolutely right to change all your passwords.
robocat 10y ago
Passwords are in HTTPS requests, and should never be in HTTPS responses (especially not cacheable responses). Only GET responses should be cached (not requests), so it seems unlikely a password would leak.

by _kst_ 10y ago

PuffinBlue 10y ago

I forced user password resets on a forum I run. It is powered by myBB. This is towards the edge of my knowledge circle but... It doesn't appear that any hashing takes place client side[0] with myBB before the password is transmitted to the server, but I may have missed it when rechecking the code. Presumably that would mean in my case users who logged in potentially had their cleartext passwords pass through Cloudflare's network when they submitted their login details. Despite being behind https, when https is terminated at Cloudflare's edge and re-encrypted to my origin server (I use full/strict crypto setting), there was the possibility for decrypted data to be held in memory and then the possibility for it to be injected into the html pages of other sites when the bug was triggered. It would be a very very small probability of actually happening, but not zero. No details from the server should have leaked because only the content of transmitted data that passed over Cloudflare could have been leaked and the comparison of the provided password to the hashed/salted one in the database would have occurred on the server and not passed over the network. So the answer is it would depend on the way the sites you use handled password transmission and comparison. Personally I'd change them, and actually have done so for sites I use. [0] https://community.mybb.com/archive/index.php?thread-88668.html https://community.mybb.com/archive/index.php?thread-88668.ht...

orthecreedence 10y ago

> What would actually have been leaked, a cleartext password or the encrypted/hashed password stored on an affected server (or both)? Depends on the app. The apps I write will do a PBKDF2 w/ 20K rounds on a password before sending to the server, which then hashes that hash again before storing/comparing. I suspect most apps just sent the username/password plaintext over SSL, meaning the plaintext passwords would have been leaked if the app used Cloudflare to terminate SSL. That said, if someone got the PBKDF2ed password hash from the SSL payload, they could just as easily use that to log into an account, but they'd have to at least do a little bit of work to break the hash if they wanted to actually crack the password. In other words, you were absolutely right to change all your passwords.

robocat 10y ago

Passwords are in HTTPS requests, and should never be in HTTPS responses (especially not cacheable responses). Only GET responses should be cached (not requests), so it seems unlikely a password would leak.