[7980] in bugtraq

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stopping "nack" `stealth' scanning.

daemon@ATHENA.MIT.EDU (Darren Reed)
Sat Sep 19 16:07:45 1998

Date: 	Sat, 19 Sep 1998 15:40:19 +1000
Reply-To: Darren Reed <avalon@COOMBS.ANU.EDU.AU>
From: Darren Reed <avalon@COOMBS.ANU.EDU.AU>
To: BUGTRAQ@NETSPACE.ORG

One of the other ways to stealth scan is observing which ports no
reply is received for.  This patch causes RST's to be generated when
sending (for example) a FIN to a listening socket, the same as in all
other occasions.  Patch provided by mycroft.

Darren


*** tcp_input.c.orig    Sat Sep 19 14:52:06 1998
--- tcp_input.c Sat Sep 19 14:24:22 1998
***************
*** 618,624 ****
                                                tiwin <<= tp->snd_scale;
                                                goto after_listen;
                                        }
!                               }
                        } else {
                                /*
                                 * Received a SYN.
--- 618,625 ----
                                                tiwin <<= tp->snd_scale;
                                                goto after_listen;
                                        }
!                               } else
!                                       goto badsyn;
                        } else {
                                /*
                                 * Received a SYN.

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