Re[2]: [VulnWatch] IMail Account hijack through the Web Interface

[Obscure <obscure () eyeonsecurity net>]

Hello Zillion,

Monday, March 11, 2002, 5:11:43 AM, you wrote:


Z> Hi all,

Z> I think this was already covered for Imail 7.04 in the following
Z> advisory:

Z> http://cert.uni-stuttgart.de/archive/bugtraq/2001/10/msg00082.html

Z> The workaround given by Ipswitch was:

Z> Turn off the "ignore source address in security check" option. This isn't
Z> a bullet proof workaround (think of proxies,nat etc) but can help to
Z> prevent abuse of this issue.

Z> zillion

Seems like this is old news ;)

As an additional workround:
In my testing, when using HTTPS (secure mode) to access your IMail
account, the referer is not being sent, meaning that clients using
HTTPS should not be vulnerable. This was tested with Internet Explorer 6
and Mozilla 0.9.8 against the tool at:
http://eyeonsecurity.net/tools/referer.html


Z> On Sun, 10 Mar 2002, Obscure wrote:

> > Advisory Title: IMail Account hijack through the Web Interface
> > Release Date: 10/03/2002
> > Application: IMail Server
> >
> > Platform: Windows NT4
> >           Windows 2000
> >           Windows XP
> >
> > Version: 7.05 or earlier
> >
> > Severity: Malicious users can easily access other people's accounts.
> >
> > Author: Obscure^ [ obscure () eyeonsecurity net ]
> >
> > Vendor Status: Informed on 21 Feb 2002, a fix was already issued to
> > customers.
> >
> >
> > Web:
> >
> > http://www.eyeonsecurity.net
> > http://www.ipswitch.com
> >
> >
> >
> > Background.
> >
> > (extracted from
> > http://www.ipswitch.com/Products/IMail_Server/index.html)
> >
> > The 20-Minute E-Mail Solution.
> > IMail Server is an easy-to-use, web-enabled, secure and
> > spam-resistant
> > mail server for Windows NT/2000/XP. It is the choice
> > of businesses, schools, and service providers.
> >
> > A Great Price-Performer.
> > Unlike Microsoft® Exchange and Lotus® Notes, which are costly to
> > deploy and cumbersome to administer, IMail Server is easy
> > to install and easy to manage. It has a simple pricing structure and
> > is scalable to thousands of users per server.
> >
> >
> > Problem.
> >
> > When a user logs in to his account through the Web interface, the
> > session authentication is maintained via a unique URL.
> > By sending an html e-mail which includes an image at another server,
> > an attacker can easily get the unique URL via the
> > referer field in the HTTP header.
> >
> >
> > Exploit Example.
> >
> > http://eyeonsecurity.net/tools/referer.html
> > A CGI script sends an e-mail with an attached image, pointing to
> > another CGI script which sends the referer URL to the
> > attacker.
> >
> >
> > Fix
> >
> > Upgrade to IMail 7.06. The fixed version checks for the IP. The
> > authentication now relies on the unique URL and the IP
> > address. Of course users who log in to IMail Web interface from
> > behind
> > proxies, are still vulnerable.
> >
> >
> > ps. this same vulnerability effects Excite WebMail. The Excite guys
> > did not contact me back.
> >
> >
> > Disclaimer.
> >
> > The information within this document may change without notice. Use
> > of
> > this information constitutes acceptance for use in an AS IS
> > condition. There are NO warranties with regard to this information.
> > In no event shall the author be liable for any consequences
> > whatsoever
> > arising out of or in connection with the use or spread of this
> > information. Any use of this information lays within the user's
> > responsibility.
> >
> >
> > Feedback.
> >
> > Please send suggestions, updates, and comments to:
> >
> > Eye on Security
> > mail :   obscure () eyeonsecurity net
> > web  :   http://www.eyeonsecurity.net


-- 
Best regards,
 Obscure                            mailto:obscure () zero6 net