Roger,
Simply knowing a username doesn't necessarily imply a weakness in security. For
instance, I can be pretty sure that the e-mail server that you sent this
message from has your username (Roger.Olstad, or something similar). Simply
knowing that doesn't help much.
Of course, in theory, knowing a username and guessing a password is easier than
guessing both a username and password.
Brute-forcing over the web isn't usually a good idea-- it generates too much
traffic and takes far too long in most cases. I'm sure there are some good
tools to test password strength and to brute-force them yourself.
All in all, I wouldn't worry, just because a username is known. Administrator,
root, admin, postmaster, etc are all "known", but the password is the tricky
thing. If you want to improve your security, implement a better password policy
( >= 8 characters, no dictionary words, etc).
M
Michael Scovetta
Computer Associates
Senior Application Developer
-----Original Message-----
From: Ølstad, Roger [mailto:Roger.Olstad@pax.priv.no]
Sent: Wednesday, May 18, 2005 8:05 AM
To: pen-test@securityfocus.com
Subject: penetrating web-based authentication if you know one of the usernames
Hi!
I have this web-based service/directory which offers users access through a
username/password-authentication process. I am wondering what if some of the
usernames are compromised, and I actually don't want to change the username?
Are there any tools able to run some kind of bruteforce-attack or something,
against my web-authentication? Other alternatives? Do I really have to consider
my whole system as compromised just because a username may be lost?
In addition, does anyone know of any tool that can help me audit the web-server
regarding to passwordpolicy, passwordstrength etc.
I appreciate all relevant answers :-)
Very best
R
-----Original Message-----
From: Erik Kamerling [mailto:ekamerling@snaplen.com]
Sent: 17. mai 2005 16:13
To: pen-test@securityfocus.com
Subject: Re: Cisco VPN Concentrator GUI
My original response never made it so here it is again.
On Sunday 15 May 2005 23:09, kaps lock wrote:
i cant find any vulenrabilites on the net ....to
explain to the person....only thing i can think of is
brute forcing the username pasword field...which is
again a challenge for web vpn..any ideas??
thanks
Hi Kaps Lock,
You might want to impart info to your client regarding the common sense
security measure of limiting access to the HTTPS interface on the
concentrator to only trusted management hosts or internal networks.
Enabling uncontrolled public side HTTP(S) management of a VPN concentrator
gives out way more info re: their VPN than most people would want IMHO.
I don't believe HTTP(S) is enabled by default (at least on a public interface)
on a 3000 series concentrator so someone turned it on most likely.
3000 series concentrators are vulnerable to a SSL attack prior to version
4.1.7.A so you might want to point this out to them. The attacker does not
need to authenticate and can effectively reload the device or make it drop
user connections.
Here is the advisory ->
http://www.cisco.com/warp/public/707/cisco-sa-20050330-vpn3k.shtml
And a more general view on 3000 vulnerabilities ->
http://www.cisco.com/warp/public/707/vpn3k-multiple-vuln-pub.shtml
Best Wishes,
Erik Kamerling
