Re: Re: mail server vulnerability

[Jared Curtis <jared () w00ttech com>]

You can't block telnet access to port 25.  When you telnet to port 25
you're not connecting to telnetd, your're connecting to the smtp
service.  SMTP is human readable and a telnet client can display the
output, you could also use netcat, to connect.  Trying to block telnet
access to port 25 will not work as there is nothing to block.  When
you connect using the telnet program you're acting just like a remote
MTA.

On Fri, Feb 20, 2009 at 7:37 AM,  <praveen_recker () sify com> wrote:
> Hi Abhishek,
>
> You can try connecting to the SMTP server using telnet,say
> c:/>telnet smtp_ip 25
> this should not be successful....so system admins should block TELNET to SMTP servers. If successful this gives u the 
> banner. Based upon version and vendor search for any exploits available for free (refer milw0rm, metasploit etc) if u 
> have commercial tools(coreimpact, saint etc) it's well and good.
> If u are good at Perl develop ur own script and start sending attacks by changing USER names, DOMAIN names etc to 
> overly long strings, format specifiers etc.
>
> Best Regards,
> Praveen Darshanam,
> Security Researcher,
> INDIA