[32828] in bugtraq
Re: Insecure IKE Implementations Clarification
daemon@ATHENA.MIT.EDU (Florian Weimer)
Sat Dec 13 14:21:59 2003
Date: Fri, 12 Dec 2003 22:45:37 +0100
To: Thor Lancelot Simon <tls@rek.tjls.com>
Cc: Aaron Adams <aadams@securityfocus.com>, bugtraq@securityfocus.com
Message-ID: <20031212214537.GA18282@deneb.enyo.de>
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From: Florian Weimer <fw@deneb.enyo.de>
Thor Lancelot Simon wrote:
> The second problem is generic to *any* IKE that can be configured to
> use a "group password" and then send a second authenticator using XAUTH.
>
> *This is probably the *most common* configuration of the Cisco "VPN client"
> implementation that you will find deployed in the field*. That's no
> surprise, because Cisco consultants, Cisco-trained consultants, and Cisco
> sales engineers push it on customers heavily as a panacea for bootstrapping
> a VPN using only a legacy authentication database.
There's also a PSIRT statement regarding this issue, and it's at best
embarrassing for Cisco engineering folks:
<http://www.cisco.com/warp/public/707/cisco-sn-20030422-ike.html>
I know several people work on XAUTH MITM attacks; I guess it will fall
in a couple of weeks. (Just sniffing the user password is easy, the
group password is typically public anyway; the remaining challenge
consists of putting together several tools to transparently fake a Cisco
VPN concentrator).
