[hypermail] Hypermail SSI Vulnerability (fwd)

FYI This was just posted to the bugtraq mailing list.

-- 
      Daniel Stenberg - http://daniel.haxx.se - +46-705-44 31 77
   ech`echo xiun|tr nu oc|sed 'sx\([sx]\)\([xoi]\)xo un\2\1 is xg'`ol

---------- Forwarded message ----------
Date: Mon, 19 Nov 2001 14:36:55 -0500
From: qDefense Penetration Testing <advisories_at_qDefense.com>
To: bugtraq_at_securityfocus.com
Subject: Hypermail SSI Vulnerability


Hypermail SSI Vulnerability
qDefense Advisory Number QDAV-2001-11-1

Product: Hypermail

Vendor: Hypermail Development (http://www.hypermail.org)

Severity: Remote; Attacker may be able to execute arbitrary commands on
servers that run Hypermail and SSI

Vendor Status: Vendor contacted; patch released

In Short: Hypermail can be used to create arbitrary files, with arbitrary
extensions, on the server, which may then possibly be used to execute SSI
commands.


The current version of this document is available at
http://qDefense.com/Advisories/QDAV-2001-11-1.html.

Details:

Hypermail converts e-mails into HTML. It is generally used to automatically
create web archives of mailing lists. When e-mails are archived,
attachments which are included are archived as well. The attachments are
not modified before archival, and they are stored under the filename
contained in the e-mail.

An attacker can therefore create an arbitrary file on the web server with
an arbitrary extension. If the server supports SSI, an attacker can include
SSI commands in a file, give it the SSI extension (normally .shtml), and
mail it. This will create the desired file on the server. The attacker can
than cause the server to execute those SSI commands by requesting the
attachment.

It should be noted that creation of arbitrary files on a web server carries
with it additional insecurites besides SSI, and therefore even servers that
do not support SSI may be vulnerable.

Solution:

Hypermail has been patched to convert .shtml extensions to .html. As of
this writing, no further correction has been taken.

Servers should never allow SSI, CGI, or any other type of server processed
content in the hypermail directory.

(C) 2001 qDefense Penetration Testing. qDefense Penetration Testing is a
subsidiary of Computer Modeling Corp.
This document may be reproduced, in whole or in part, provided that no
modifications are made and that proper credit is given. Additionally, if it
is made available through hypertext, it must be accompanied by a link to
the qDefense Penetration Testing web site, http://qdefense.com.