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SANS ISC: The Passwords You Should Never Use - SANS Internet Storm Center SANS ISC InfoSec Forums


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The Passwords You Should Never Use

New releases of bad or weak passwords lists are common[1][2] on the Internet. Those lists compile passwords that are used by people to protect (even if it's not the most appropriate term) their accounts. But passwords are everywhere and also used to control access to devices. Recent attacks like the Mirai[3] botnet which attacked IoT devices are a good example. Once infected, a device will start to search for new potential victims by scanning the Internet for some vulnerable ports (TCP/23, TCP/2323 are good examples), then brute-force the password by testing a list of well-known passwords. Those passwords are somewhere different than users' password but just as vulnerable.

While hunting, I found some interesting pieces of C source code that contained lists of passwords used by such infected devices. Keep in mind that a password considered as strong (your know the magic formula: a mix of upper/lower case characters, numbers and special characters) is useless if it is known in the wild!

Here is the list of passwords that I found to be used in the wild:

"" (empty string!)
00000000
1111
1111111
1234
12345
123456
54321
666666
7ujMko0admin
7ujMko0vizxv
888888
Zte521
admin
admin1
admin1234
administrator
anko
default
dreambox
fucker
guest
hi3518
ikwb
juantech
jvbzd
klv123
klv1234
meinsm
pass
password
realtek
root
service
smcadmin
supervisor
support
system
tech
ubnt
user
vizxv
xc3511
xmhdipc
zlxx

If you have devices configured with one of those passwords, change it as soon as possible. Even, if your devices are not facing the internet! Feel free to share your list of passwords if you found others, I'm curious.

[1] http://gizmodo.com/the-25-most-popular-passwords-of-2015-were-all-such-id-1753591514
[2] http://www.passwordrandom.com/most-popular-passwords
[3] https://isc.sans.edu/forums/diary/The+Short+Life+of+a+Vulnerable+DVR+Connected+to+the+Internet/21543

Xavier Mertens (@xme)
ISC Handler - Freelance Security Consultant
PGP Key

Xme

428 Posts
ISC Handler
I'm curious about password strength, as I've been seeing more articles indicating length is more important than a mix of case, numbers and symbols. https://uit.stanford.edu/service/accounts/passwords/quickguide is a good example, although my gut feeling keeps telling me that even at 20 characters we should have a mix of characteristics. Any thoughts on password length being the driving consideration to password strength?
Steve

5 Posts
Most of the words & phrases on this list I recognize or can work out, but this one is new to me: vizxv
Does anyone know the origins of this as a password?
TravisMcW

3 Posts
Agree. Eight (8) characters is highly insufficient for any use. And 20 character is a good level. Any average person should be able to recall a passphrase at that level (I was part of scientific research by NASA to test that theory-and I had to change to 20 or 22 characters every few days!). I think the typical psuedo-random-mix method (aA00!~) is also problematic, especially at 20 characters. There are better methods (Schneier's pseudo-abbreviation, XKCD random words, etc.) that are likely strong and easier to remember.
Brett

17 Posts
forgot to comment on Stanford's guidance. It is not good. I would guess that they are aiming at longer-is-better, but longer needs to be simpler. I'd have to run some math on this premise (see grc.com for excellent quantitative password analyis). As I said in previous post, 20 mixed characters is not mentally challenging.
By Schneier's method
Long complex passwords include characters, numbers, letters and entropy in order to get enough strength
Lcpic,n,l&eio2ges [17]

XKCD (which I enhance with numbers & characters) of same phrase
L0ng, le77ers & entropy [23]

(i have developed a couple methods that are equally as strong)
both methods above are strong as well as not so mentally challenging as typical security orthdoxy would dictate.
Brett

17 Posts
%Season%%yyyy% so Winter2016 etc.
Anonymous
I've made myself a little password test utility. It basically looks at the characters it's seen so far and makes an estimate as to how surprising the next character is. Expresses that surprise as a number of bits and adds that to a running total.

So another letter after nineteen of them isn't that surprising, BUT, a completely random ascii character is about 6.5bits per character. That's about 52bits for eight completely random printable ascii characters. If you use twenty characters matching this strength means getting just 2.6bits per character ... that's basically a single dice throw. So even if you lose a lot of bits because you're using words it will be quite difficult to get that low.

I would suggest that it's a good idea to add a symbol or two in your password. I would guess that a symbol in the middle of letters is likely to increase the "surprise" a lot. If I'm measuring it in bits I'd be looking at one symbol giving you perhaps 10bits of extra entropy just because it's impossible to know exactly where it is. But it's not _required_ because 20 letters is secure against any random attack and probably secure against a targeted attack (unless you use "internationalisation" as your password)

It's always possible to choose a bad password, whatever the rules.
UnknownNick

11 Posts
According to google, it may be a default root password for a dahua dvr
Ideaphore

2 Posts
Quoting TravisMcW:Most of the words & phrases on this list I recognize or can work out, but this one is new to me: vizxv
Does anyone know the origins of this as a password?


According to Google it may be associated with a Dahua device ( DVR/Camera ? ), as is 7ujMko0.
Ideaphore

2 Posts
Many passwords on the list are default passwords for gadgets published on internet, like https://gist.github.com/gabonator/74cdd6ab4f733ff047356198c781f27d
Anonymous

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