n.runs AG
http://www.nruns.com/
security(at)nruns.com
n.runs-SA-2008.001
25-June-2008
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Vendor: Jscape, http://www.jscape.com/
Affected Products: Jscape Secure FTP Applet
http://www.jscape.com/sftpapplet/index.html
Vulnerability: SSH Host key is not verified allowing
man-in-the-middle attacks
Risk: Medium
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Overview
--------
The JSCAPE Secure FTP Applet suffers from a man-in-the-middle vulnerability.
JSCAPE software has been deployed in a wide array of industries including
aerospace, banking, communications, education, insurance, finance,
government and software. With customers in more than 50 countries worldwide
the following is a small sample of companies who use JSCAPE products and
services. Customers include Boeing, SUN, ISS, SAP - See
http://www.jscape.com/clients.html for more details.
The JSCAPE Secure FTP Applet is a secure FTP client that runs within Java
enabled web browsers. The software supports SFTP (FTP over SSH) and FTPS
(FTP over SSL) for encrypted file transfer.
Description
-----------
To prevent man-in-the-middle attacks it is important to check the
authenticity of the destination server by verifying the host key of the
server when establishing the SSH connection. With previous versions of the
JSCAPE Secure FTP applet it was not possible to verify the authenticity of
the destination server.
Impact
------
When using affected versions of the JSCAPE secure FTP applet, users are not
able to identify man-in-the-middle attacks. The supposedly secure connection
is no longer secure. An attacker is able to eavesdrop on the connection in
order to extract username and password or take over the initiated session.
Solution
--------
Upgrade to version 4.9.0 or above
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Vendor communication:
2006/04/12 n.runs sends a Vulnerability Notice informing Jscape
about the nature of the problem and the impact.
2006/04/13 Jscape acknowledges and ask for more details
2006/04/13 n.runs gives more details
2007/07/26 n.runs asks for feedback and if the problem has been
patched
2007/07/26 Jscape replies "We do not have a release date yet for
this task"
2007/07/26 n.runs asks whether they can offer a estimate when the
patch will be available
2007/07/26 Jscape answers again "We do not have a release date yet
for this task"
2008/02/19 n.runs requests a statement to be used in the advisory as
there seems to be no intention to patch and argues "you
deem this problem as low yet it renders the *secure
connection* insecure."
2008/02/20 Jscape promises to "continue to look into this issue and
notify you when a patch is available".
2008/02/25 n.runs notifies Jscape that an advisory will be released
by the end of the week if they do not patch the flaw
n.runs reported roughly 2 years ago.
"Given the long time this has already been reported
(12/2006), and the criticality of this issue, I would
expect a patch to be ready by the end of the week. If the
patch is not available until the end of this week
(29.02.2008) I'll proceed with the advisory"
2008/02/29 Jscape notifies n.runs that the flaw has been patched
2008/06/01 n.runs verifies the patch and confirms that
man-in-the-middle is no longer possible if the user does
not accept the new key. n.runs however recommends that
Jscape warns the users of the security implications of a
new SSH Host key rather then simply displaying "New Host
key".
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Credits
-------
Vulnerability discovered by Frank Dick and Thierry Zoller of n.runs AG.
About n.runs
------------
n.runs AG is a vendor-independent consulting company specializing in the
areas of: IT Infrastructure, IT Security and IT Business Consulting. In
2007, n.runs expanded its core business area, which until then had been
project based consulting, to include the development of high-end security
solutions. Application Protection System - Anti Virus (aps-AV) is the first
high-end security solution that n.runs is bringing to the market.
Advisories can be found at : http://www.nruns.com/security_advisory.php
Copyright Notice
----------------
Unaltered electronic reproduction of this advisory is permitted. For all
other reproduction or publication, in printing or otherwise, contact
security@xxxxxxxxx for permission. Use of the advisory constitutes
acceptance for use in an "as is" condition. All warranties are excluded.
In no event shall n.runs be liable for any damages whatsoever including
direct, indirect, incidental, consequential, loss of business profits or
special damages, even if n.runs has been advised of the possibility of such
damages.
Copyright n.runs AG. All rights reserved. Terms of use apply.
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