Vulnerability Note VU#476267

Standard HTML form implementation allows access to IMAP, SMTP, NNTP, POP3, and other services via crafted HTML page

Overview

I. Description

An intruder can send certain kinds of data to services that he is not ordinarily able to reach. By crafting the data such that it is redirected through any program the victim uses to render the malicious HTML, the intruder is able send that data to any services that the victim can send data to. If the victim is either tricked into clicking on a form submission button or a JavaScript program submits the form on behalf of the victim, the intruder's data may be sent to the service specified. Since the connection originates from the victim, any access control lists or restrictions designed to protect the server (such as a firewall) may not be effective. The data that the intruder is able to send is usually encoded as "multipart/form-data" by the browser, which necessarily inserts some header and encoding metadata, and is subject to any limitations of the protocol it attempts to attack.

This vulnerability has been called "cross-protocol scripting."

II. Impact

An intruder may be able to use this vulnerability to send mail (Spam), post News, get or send files from or to an FTP server, or send data to an HTTP server. It may even be possible to exploit a vulnerability in one of these services through this problem, though we are not certain of that at this time. For example, an intruder may be able to exploit this problem as a means of attacking a vulnerable web server that would ordinarily be protected by a firewall. Additionally, it may be possible for an intruder to cause denial-of-service conditions within the network by sending unexpected data to network services. This unexpected data may crash or hang the services receiving the data.

III. Solution

Upgrade your application according to your manufacturer's recommendations, if any. Additionally, do not rely solely on firewalls to provide a guarantee that an intruder can not reach a service. Keep internal systems up to date with respect to patches and workarounds.

Systems Affected

Vendor	Status	Date Notified
Apple Computer, Inc.	Unknown	15-Aug-2001
Berkeley Software Design, Inc.	Unknown	15-Aug-2001
Cray Inc.	Unknown	17-Aug-2001
DeC	Unknown	15-Aug-2001
FreeBSD, Inc.	Not Vulnerable	17-Aug-2001
Fujitsu	Unknown	17-Aug-2001
Hewlett-Packard Company	Unknown	15-Aug-2001
Microsoft Corporation	Vulnerable	16-Aug-2001
MiT Kerberos Development Team	Unknown	15-Aug-2001
Mozilla	Unknown	4-Feb-2008
NEC Corporation	Unknown	15-Aug-2001
NetBSD	Unknown	17-Aug-2001
Netscape Communications Corporation	Vulnerable	16-Aug-2001
OpenBSD	Unknown	15-Aug-2001
Red Hat, Inc.	Unknown	15-Aug-2001
Sequent Computer Systems, Inc.	Unknown	15-Aug-2001
SGI	Unknown	15-Aug-2001
Siemens Nixdorf	Unknown	15-Aug-2001
Sony Corporation	Unknown	15-Aug-2001
Sun Microsystems, Inc.	Unknown	15-Aug-2001
The SCO Group (SCO Linux)	Vulnerable	20-Aug-2001

References

http://www.remote.org/jochen/sec/hfpa/index.html
http://www.securityfocus.com/bid/3181
http://eyeonsecurity.org/papers/Extended%20HTML%20Form%20Attack.htm
http://www.mozilla.org/projects/netlib/PortBanning.html
http://ha.ckers.org/blog/20060920/imap-vulnerable-to-xss/
http://www.ngssoftware.com/research/papers/InterProtocolExploitation.pdf
http://www.gnucitizen.org/blog/hacking-the-interwebs
http://aaron.weaver2.googlepages.com/CrossSitePrinting.pdf
http://ilia.ws/archives/145-Network-Scanning-with-HTTP-without-JavaScript.html

Credit

The CERT/CC thanks Jochen Topf <jochen@remote.org> for reporting this vulnerability. We would also like to thank Wietse Venema and Steve Bellovin for their assistance in understanding this vulnerability. Additionally Wietse Venema coined the name "cross-protocol scripting."

This document was written by Ian A. Finlay and Shawn V. Hernan.

Other Information

Date Public:	2001-08-15
Date First Published:	2001-08-16
Date Last Updated:	2008-02-04
CERT Advisory:
CVE-ID(s):
NVD-ID(s):
US-CERT Technical Alerts:
Metric:	15.00
Document Revision:	49

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