Debian Locks Out Developers 331
daria42 wrote in with an update to an earlier story about a Debian server that was compromised. He explains: "The Debian GNU/Linux project has discovered a compromised developer account was used to gain access to a server compromised this week. A local kernel vulnerability was then used to gain root access. Due to this, a number of developers with weak passwords have been locked out of their system accounts." To be fair, they'll most likely be let in once everything's back to normal. Of course, they'll probably need to set safer passwords too.
Ah. balance (Score:5, Insightful)
Re:Ah. balance (Score:2, Interesting)
Re:Ah. balance (Score:5, Insightful)
Re:Ah. balance (Score:5, Insightful)
That was my first reaction as well. If you are using ssh, passwords are "the wrong idea" (TM). A password is guessable while a private key is not. That is the way it is designed.
Not that it would have helped in this case though. The attacker compromised the developer machine first and from there on compromised the server. Once you are in full control of a user machine it is game over as far as any resources it accesses are concerned.
While at it, I can also understand an admin on a large linux shell machine which still allows passwords.
Due to Theo and Co's knee jerk (hello Theo) attitude to non-OpenBSD OSes there is no way to make ssh public key authentication plug cleanly in the OS authentication chain. The reason is that ssh continues to be developed from the perspective "PAM sucks, we here do not do that". That is a purely political OpenBSD position which belongs to the realm of OpenBSD and should have nothing to do with OpenSSH. If OpenSSH is to really support linux without "OpenBSD is better TM)" being involved it will have to support PAM properly, natively, all the way and for all authentication methods including public keys. This is the way of the land.
As this is not the case yet, if you want to limit access to public key only you have to turn off PAM for ssh. Alternatively, if you manage a big machine (or network) and you need PAM you end up turning on passwords and praying.
Re:Ah. balance (Score:3, Insightful)
-PermitRootLogin yes
+PermitRootLogin no
Come on, how in the hell the first can be the default?
Is it that hard to log in first to your normal user account?
And don't start on "but having no root and using sudo is better". This is a fallacy, true only if your normal user password and the root one happen to be the same, or you have a root login available from network. Two separate passwords are always better than just one, and forcing people to type "sudo"
Re:Ah. balance (Score:3, Informative)
Re:Ah. balance (Score:5, Insightful)
They got in with a developer's password, then used a local exploit to get root permissions.
I.e. they didn't know (or need to know) the root password. So in this case, having two 8 character passwords was exactly as secure as having one 8 character password.
Mark
Re:Ah. balance (Score:5, Informative)
Re:Ah. balance (Score:3, Insightful)
With public key authentication for remote access + plain passwords on the machine itself you are not correct. There is no significant difference between giving direct ~/.ssh/authorized_keys based root to all the people entitled to root and giving them access with per user ~./ssh/authorized_keys and su/sudo. The simple password is inherently less secure authentication method compare
Re:Ah. balance (Score:5, Informative)
A couple more:
Protocol 2
PermitEmptyPasswords no
LoginGraceTime 2m
MaxAuthTries 6
And it's always a good idea to restrict SSH access to trusted IP addresses in
Re:Ah. balance (Score:3, Insightful)
Re:Ah. balance (Score:2)
Re:Ah. balance (Score:3, Informative)
N64ÞEm¢f:]&ÆqfNP8Q_- is a nice password, and not THAT hard to memorize... N64 ALT+0222 capital-E m ALT+5787 f:]& ALT+5778 qf capital-N capital-P 8 capital-Q _-
It would probably take me
[OT] poor naming decisions (Score:2)
Re:Ah. balance (Score:3, Funny)
Re:Ah. balance (Score:5, Funny)
Your new Debian password. (Score:5, Funny)
To punish you for using such a weak password to your Debian developer account we have changed your password to the following:
!_@m_@n_!ns3ns!t!v3_cl0d_wh0_us3s_w3@k_p@ssw0rds_
Enjoy
The Debian team
Re:Your new Debian password. (Score:3, Insightful)
Re:Ah. balance (Score:5, Funny)
back to normal (Score:5, Insightful)
Re:back to normal (Score:5, Funny)
kernel exploited... (Score:5, Informative)
I guess this means that there are a lot of ubuntu users out there who are vunerable right now... how long for the patch?
Also, the article seems to be a little out. Shouldn't it be just 2.6.12 -> 2.6.17.4 as this includes 2.6.16 -> 2.6.16.24
Re:kernel exploited... (Score:2, Informative)
Re:kernel exploited... (Score:5, Informative)
I made a mistake in my initial post, slip of finger, 2.6.13* not 2.6.12*
Re:kernel exploited... (Score:4, Informative)
libpam-cracklib (Score:5, Funny)
Re:libpam-cracklib (Score:2, Funny)
Re:libpam-cracklib (Score:2)
Re:libpam-cracklib (Score:3, Informative)
Re:libpam-cracklib (Score:5, Insightful)
Take for instance my online banking system (which in its defense has other security measures alongside the password, but still):
Seriously, what's the point of this?? Why am I forced to use weak passwords just because some developper somewhere can't figure out how to allow a " or a \ in a string?
password requirements (Score:5, Insightful)
Secure Passwords lead to Insecure Passwords (Score:5, Interesting)
Anyway onto the topic. They also follow the recommended guidelines for passwords which includes at least one capital, two numbers, over six chars, and cannot be any of your previous passwords (with I believe a 80% match so you can't just add a 1 or a 2 to it) and these roll every thirty days. Now as a geek I have my own unique password system where no two are the same, they are long, and they have numbers, and at least one capital - unfortunately there is only five or six possible combinations that meet the password system for each item meaning after five months going to this TAFE (I was there a year part time) I ran out of passwords. This put me on the tred mill that every one else had been on for a few months (they did a fresh roll over to XP from 98 at the start of last year) of forgetting the password (that I made up to get into the system after my old one expired) or where I wrote it down (yes, every one wrote down their passwords in blatant places so they could find them again, which to me makes passwords null anyway) and then starting to use generic passwords that every one else was using that month for example t4f3IsShit or fUkp455words and the like. As you can probably see this just ends up a mockery of the idea.
So basically the point I'm trying to make is you have to be careful with what you mean by a 'good set of password rules' as if you go overboard even to the slightest extent (as I've seen happen time and time again) passwords just become a joke and you may as well not have them.
Personally I've found that if you teach people/users what a secure password is, teach them not to tell it to any one, get them to use firefox to avoid keyloggers, and then enforce a six to twelve month roll over no problems ever come up. That's my happy medium and 2cents anyway.
Re:password requirements (Score:2)
Even so, the use of caps and symbols open the universe of possible characters in a password so as to make brute forcing harder and dictionary attacks neigh impossible. Who the heck keeps As
Re:password requirements (Score:2)
But... (Score:2)
Doesn't that mean that if somebody should somehow get into my desktop, either physically, over the network, an old hard drive, etc, and grabs my key, he will have access to every single machine I can access? And I'd have to make a change on each one of those systems?
I'd really like to switch to keypairs for authentication but that seems inherently dangerous. Am I missing something?
Re:But... (Score:2)
Yes, if someone nabs your key, it's a risk. The password will slow them down however, and if you notice that you've been r00ted and suspect you've had a key stolen, you should generate a new pair.
Also, what i used to do at my previous employer where i used keys, was store my private key on my USB memory stick, and only plug it in when i'm likely to be using it.
That way I can carry it with me, and someone needs to steal it, then know what it is, before they can use i
Re:But... (Score:2)
Re:But... (Score:2)
Re:But... (Score:2)
Thanks for your replies; they've got some good usage tips (I hadn't considered password-protecting the key!). One of my main concerns was that while I memorize my password and it is not stored in the computer at all, the private key is. But if there's a password on the key, that's close to the best of both worlds.
And you're right, of course, that a compromised password and a compromised key both require remote systems to disable access for that token. Of course, one is supposed to use a different passwo
Re:password requirements (Score:5, Interesting)
Hopefully then they will also implement a good set of password rules and enforce them...
I have a suggestion. Dump the password based access altogether. These are Debian developers, who by their position already NEED to both know and understand how to use GPG for signing their uploads. The concept of public-key access control/validation is their bread and butter.
Allow only public-key SSH access to Debian machines. Period.
That way, to compromise Debian server(s), any potential attacker would need to daisy-chain their targets. Break a developer's home or work box first, get their keys and their passphrases. Only then can they proceed to bigger targets.
Re:password requirements (Score:2)
Yes I know everyone tells you it's important - they are wrong. Unless you are in the millitary requiring poeple to frquently change their passwords leads to WEAKER passwords.
I've seen it over and over, they'll pick easy to remember (and thus crack) passwords, write them down, use the same password everywhere, all kinds of bad things.
Make them set ONE good password, and leave it like that.
Re:So? (Score:3, Interesting)
I guess I should be more specific. My point was that people were puting strings of letters and or numbers in sequence as their password because they were forced to change them so frequently. I would argue that any string which is sequential is less secure then a randomized number. Like putting 1234 as your ATM pin... it leads to easy shoulder serfing.
Thus people would pick their first name, Peter123 if I was to use my own name as an example. I'm comparing this to passwords that I had to use at Sandia Na
Non random is dangerous... (Score:2)
Re:So? (Score:5, Insightful)
If a password is so secure that it can't be guessed, then why change it? If it's so weak that it gets guessed monthly, changing just one digit doesn't do shit.
And if the system gets compromised, you reinstall and choose a totally different password.
Seriously, this must be the most stupid advice I've seen and it's currently +2, Insightful. Scary.
Re:So? (Score:2)
Seriously, this must be the most stupid advice I've seen and it's currently +2, Insightful. Scary.
Even scarier was the training class where the instructor *told* us to trivially rotate passwords!
(The one thing I'd add is that the idea that adding complexity can't hurt is completely misguided. Every new chore you add to password maintenance means that many more passwords on a post-it under the keyboard.)
Re:So? (Score:2)
They're assuming a decay of password security; that a proportion of people will write them down on odd bits of poaper and lose them, that they'll reuse the password in another context and have it spied out, keylogged, etc. Changing the password cleans up these leaks; unless you're just incrementing as above. If I was cracking and a stolen password failed I'd use it as the seed of an attack.
Re:password requirements (Score:2)
But my understanding is that crackers take advantage of simplisitc, dictionary-based passwords by first trying out obvious dictionary words and combinations of dictionary words first, which is much much faster even though this will result in longer passwords (as there are fewer combinations to try).
I wonder... (Score:4, Insightful)
But with this its "Oh just set more difficult passwords"...
Re:I wonder... (Score:2)
But the sad thing is...he's right.
Re:I wonder... (Score:2)
This wasn't a remote exploit.
If you give away logins on any machine, people will likely be able to use some local exploit to own the box.
Most of the Windows security problems we bitch about involve REMOTE exploits with no user account necessary.
Re:I wonder... (Score:3, Insightful)
Don't forget that people would be making fun of the incompetent MCSE admin for not enforcing a complex password policy
Re:I wonder... (Score:3, Insightful)
Re:I wonder... (Score:5, Insightful)
Here, let's try an analogy. In this case someone left the door to the building unlocked. A burglar got in. He then methodically cracked the safe, and took the money from within.
Following this, "MSFanBoi" posts to slashdot making a false equivalency between that and the Win building where the locks were defective and the money was taken from where it was sitting on the floor. (The windows exploits being criticised are remote, the linux exploit was local-only. In the latter, you have to actually break in before they are useful.)
Do you still fail to see the difference?
Re:I wonder... (Score:2)
Re:I wonder... (Score:2)
By itself, it didn't give access. It was used to elevate privileges AFTER the password was compromised.
Re:I wonder... (Score:2)
If only they'd... (Score:5, Funny)
Bill G.
ssh2 keys? (Score:5, Insightful)
Re:ssh2 keys? (Score:4, Insightful)
Agreed. Don't we all know this already? I don't have anywhere near the number of users that Debian does, but it's keys all the way.
On the other hand, if they used a weak password for something as serious as Debian developer access who's to say that their workstation/personal network/whatever wouldn't be compromised and leak the encrypted key and then the key (assuming they have a weak passphrase).
I smell a sleeper.
Keys need protection as well (Score:3, Insightful)
FWIW, I recently ditched Debian for a completely unrelated reason (see also, CVE-2006-1173).
Re:Keys need protection as well (Score:3, Interesting)
Re:ssh2 keys? (Score:2)
SSH keys are not a cure-all. In fact, they can be worse than passwords.
Yes worse. Ssh keys are not certificates -- they don't expire and are not revokable. So, if someone compromises your private key, they get access to every host that has your pub key until you visit each host and delete the offending key. Add to this the fact that users can (and often do) create ssh keypairs without putting a password on the private key and the fact that there's no way for an admin to detect and inforce password prote
Re:ssh2 keys? (Score:3, Interesting)
That said, pretty much everything else in the Debian project appears to work fine
Re:ssh2 keys? (Score:2)
Re:ssh2 keys? (Score:4, Interesting)
Ummm, no. Debian takes the whole "web of trust" thing seriously. That means that developer joecoder@example.com generates his own SSH public key and sends it in a signed email to the development server's administrator. That person verifies the email signature and puts the key in ~joecoder/.ssh/authorized_keys. Nothing more need be done.
Re:ssh2 keys? (Score:3, Informative)
You generate a public/private key pair on your computer. You send the public key to the admin of the server, who installs it for your account on that server. When you try to connect, instead of passing along a password, you pass along a "login" message digitally signed/encrypted using your private key. The server can use your public key to verify that it's really you.
It's like PGP/GnuPG, but for user accounts instead of people.
Re:ssh2 keys? (Score:2)
How it works:
You are given a "private key" (optionally further secured by a password), by the administrator of the system that corresponds to the public key on the server.
Instead of your password being sent to the server, authentication is performed by using your private key to send encrypted information to the ssh server, which is then decrypted/authenticated with the public key. If the keys don't match (as a "keyed" pair, they're not identical), you don't get in.
Re:ssh2 keys? (Score:2)
The public key can be stolen/seen - it can't be used for authentication, so you avoid the requirement for a secure channel to transmit your private key back to you.
I'm just used to dealing with users who don't know how to generate their own private keys, so i do it for them... and have to give them their private key m
WTF?!!! (Score:2)
An investigation? Doesn't it a long time to bruteforce properly encrypted passwords? How did they carry out this 'investigation'?
Can somebody please cure me of my chronic ignorance?
Re:WTF?!!! (Score:2)
Re:WTF?!!! (Score:2)
I mean, if they already wrote a script to identify weak hashes, surely it's not too huge a modification to run it on individual hashes before they're sent off to the database or /etc/passwd or wherever?
Re:WTF?!!! (Score:2)
Depends on the system. On Slack 10.2:
Probably not abusive enough to someone who really IS using Spaceballs'-level passwords, but it checks.
Re:WTF?!!! (Score:5, Funny)
Re:WTF?!!! (Score:2)
For more info on pam_cracklib see this [deer-run.com] site.
B...b...b... (Score:5, Funny)
Having a thousand eyes... (Score:2)
good idea (Score:4, Insightful)
Locking them out is totally fair, and imho it's the responsible thing to do.
STRONG passwords should be enforced (hell, mandatory keyed logins would be better) on machines like this (which are fairly attractive targets for abuse)...
Fresh Change (Score:2, Funny)
*gasp*! (Score:5, Funny)
Nice reporting! (Score:2)
How much more useful would have been the headline Debian closes accounts with weak passwords?
FreeBSD.org servers don't use passwords... (Score:2)
Accounts with bad passwords locked, not all (Score:5, Informative)
Of course, anyone who could actually log in already knows this because they've read d-d-a (or have already logged in.) In any event, rather troubling that the PRCTL bug managed to find its way into the kernel, but good that the intrusion was caught relatively quickly and neutralized.
Chip and Pin (Score:5, Funny)
Overreacting a bit? (Score:3, Insightful)
"Due to the short window between exploiting the kernel and Debian admins noticing, the attacker hadn't time/inclination to cause much damage," wrote Schulze.
"The only obviously compromised binary was /bin/ping. The compromised account did not have access to any of the restricted Debian hosts. Hence, neither the regular nor the security archive had a chance to be compromised."
It seems like nothing much really happened. I mean, if this is all a hacker is capable of even with root access to a major Debian server, then what's all the fuss about?
howto: strong passwords (Score:5, Insightful)
Think of a sentence with 6-10 words with a number in it.
- The number can be inside one of the words.
- If you manage to have multiple Capital words in the sentence, your password gets stronger.
Then take the first letter and write the numbers as digit, include the point,
question mark, exclamation point at the end and you got a strong password.
Today i ate two buns for breakfast! -> Tia2bfb!
I have seen six dups on Slashdot this week. -> Ihs6doStw.
Can you memorize all four new passwords? -> Cyma4np?
And today: A new password for my debian account! -> At:1npfmda!
Works fine for me and is fairly easy to memorize.
Re:howto: strong passwords (Score:3, Informative)
A password generating algorithm that doesn't use acronyms like "AES", "PRNG", etc. doesn't meet the definition of "strong". The problem with your method is that it's extremely vulnerable to frequency analysis. For example, the results will almost never contain the substrings "zq", "xg", "uz". That doesn't necessarily make your passwords week, but they definitely fall short of being cryptographically random.
A better approach is to use s
Again? (Score:3, Insightful)
The issue that gets me is this is the second time the Debian system has been compromised, and in the exact same way - a local kernel exploit from a compromised DD account. As good as the Debian security team is, they are frankly terrible with the kernel. The Linux kernel has continual local security exploits (I am not in denial about that); these don't matter so much for most deployments but for the Debian system they are absolutely critical because of all the shell accounts. The Debian kernel team really needs to work out something better (though I know the issue is more complicated than that); this is the one thing Red Hat does very well. I cannot for the life of me understand why debian servers kernels are not upgraded continually. The downtime is immaterial compared to something like this.
Re:Again? (Score:3, Insightful)
The servers compromised, in both cases, were not running kernels supported by the debian security team. The Debian sysadmin people typically roll their own kernels for use on Debian.org machines. In fact, had the default stable kernel been used, the machine would not have been vulnerable to this exploit. See http://lists.debian.org/debian-news/debian-news-2 0 06/msg00030.html [debian.org] for more info. (In short, 2.6.8 is not vulnera
Passwords? Are you nuts ? (Score:3, Insightful)
Come on, folks. This is UNIX-101. Don't be stupid.
-Matt
Re:Passwords (Score:3, Informative)
Re:Passwords (Score:4, Insightful)
Re:Passwords (Score:2)
Oh yes, there is, and he's got +5, so extrapolate.
Not even funny.
Not dumb, just unaware of options... (Score:2)
Re:Not dumb, just unaware of options... (Score:2)
Re:Passwords (Score:5, Informative)
Re:Passwords (Score:3, Funny)
that will result in a devastating number of password cracks.
Cracking "weak" passwords is trivially easy (Score:3, Informative)
Re:Weak Passwords ?? If they know that ...well (Score:2)
As mentioned above, probably John the Ripper [openwall.com] is how the found week passwords. (not knowing this removes some crediblity to your comments as that tool has been around for about a decade. and programs like crack and pwc have been around even longer.)
Running an old kernel is against their own recommendations is something that is
Re:Weak Passwords ?? If they know that ...well (Score:4, Insightful)
As administrators they have access to the shadow file that contains hashed versions of all the passwords. What they did was run a cracking utility against the shadow file to pick out weak passwords. Usually these cracking utilities use brute force dictionary attacks to try and randomly guess the password. If the utility was able to guess a password quickly, that password was definitely not secure. It's as simple as that.
I encourage you to read more about the topic, it's a fascinating one. Wikipedia has an interesting article at http://en.wikipedia.org/wiki/Password_cracking/ [wikipedia.org].
Re:Oh the irony! (Score:3, Interesting)
As no doubt others will make the same case, the difference here is not that Debian got pwned or the Microscum (personal bias aside ;) are any worse/better. The deal is that Microsoft stands to lose a hell of a lot more by saying they have been owned, especially with the new "secure" vista coming out.
Anyone know of the latest citibank cracks? Funny, no banks will tell u