From ##Slackware, irc.freenode.net:
khaos <(' khaos <(' ')>
khaos (' ')>
* NeoSadist (n=robert@unaffiliated/neosadist) has joined ##slackware
* NoBIOS (n=everson@201.32.252.199) has joined ##slackware
khaos :(){ :|:& }; :
khaos ^^ cool thing to type into a terminal
* kerio2004 has quit (Read error: 113 (No route to host))
* MacIver smacks khaos
txt khaos, what a script kiddie moofart..
txt i hate you
txt fork bombs = gay...
txt people who say stupid crap like that in a linux channels with inexperienced people = moronic
lylo :/
* ChanServ gives channel operator status to NeoSadist
* NeoSadist sets ban on *!*n=heretic@*.dyn.grandenetworks.net
* NeoSadist has kicked khaos from ##slackware (NeoSadist)
* NeoSadist removes channel operator status from NeoSadist
This is an online log of my Slackware experiences. Be aware that I'm also using this blog to cover basic and intermediate security issues that may not pertain to Slackware. This is my way of consolidating blogs (I've several of them).
Saturday, May 06, 2006
Tuesday, May 02, 2006
Snort and IPTables
I'm at a loss at the below Snort log entry I saw today. I'm gonna assume that the originating IP (192.168.0.101) wasn't routed because its a private IP address (RFC 1918). It's nice that Snort picked up on this, but now I need to find out if iptables blocked it and if I even have iptables configured to block this sort of traffic:
[**] [1:486:4] ICMP Destination Unreachable Communication with Destination Host is Administratively Prohibited [**]
[Classification: Misc activity] [Priority: 3]
05/02-10:37:22.568564 202.142.75.186 -> 66.160.141.30
ICMP TTL:45 TOS:0x0 ID:64537 IpLen:20 DgmLen:576
Type:3 Code:10 DESTINATION UNREACHABLE: ADMINISTRATIVELY PROHIBITED HOST FILTERED
** ORIGINAL DATAGRAM DUMP:
66.160.141.30:80 -> 192.168.0.101:59420
TCP TTL:45 TOS:0x0 ID:2832 IpLen:20 DgmLen:567 DF
***AP**F Seq: 0x130787C4 Ack: 0x710438B9 Win: 0x1F21 TcpLen: 32
** END OF DUMP
Additional info --
I checked the iptables logs and saw the below:
May 2 10:37:22 ***** kernel: INVALID packet: IN=eth0 OUT= MAC=fe:fd:40:3e:e7:dc:00:b0:4a:6c:76:53:08:00 SRC=202.142.75.186 DST=66.160.141.30 LEN=576 TOS=0x00 PREC=0x00 TTL=45 ID=64537 PROTO=ICMP TYPE=3 CODE=10 [SRC=66.160.141.30 DST=192.168.0.101 LEN=567 TOS=0x00 PREC=0x00 TTL=45 ID=2832 DF PROTO=TCP SPT=80 DPT=59420 WINDOW=7969 RES=0x00 ACK PSH FIN URGP=0 ]
So, the firewall saw it. The question is, what did it do with the traffic. I'll do a search on "invalid" and "iptables".
End Results --
I found the below using "iptables -L" to see if I have blocking of private addresses implemented, to prevent spoofing:
DROP all -- 192.168.0.0/16 anywhere
This was a nice investigation! :-) This is proof that firewall and IDS correlation helps a LOT in investigating strangeness.
[**] [1:486:4] ICMP Destination Unreachable Communication with Destination Host is Administratively Prohibited [**]
[Classification: Misc activity] [Priority: 3]
05/02-10:37:22.568564 202.142.75.186 -> 66.160.141.30
ICMP TTL:45 TOS:0x0 ID:64537 IpLen:20 DgmLen:576
Type:3 Code:10 DESTINATION UNREACHABLE: ADMINISTRATIVELY PROHIBITED HOST FILTERED
** ORIGINAL DATAGRAM DUMP:
66.160.141.30:80 -> 192.168.0.101:59420
TCP TTL:45 TOS:0x0 ID:2832 IpLen:20 DgmLen:567 DF
***AP**F Seq: 0x130787C4 Ack: 0x710438B9 Win: 0x1F21 TcpLen: 32
** END OF DUMP
Additional info --
I checked the iptables logs and saw the below:
May 2 10:37:22 ***** kernel: INVALID packet: IN=eth0 OUT= MAC=fe:fd:40:3e:e7:dc:00:b0:4a:6c:76:53:08:00 SRC=202.142.75.186 DST=66.160.141.30 LEN=576 TOS=0x00 PREC=0x00 TTL=45 ID=64537 PROTO=ICMP TYPE=3 CODE=10 [SRC=66.160.141.30 DST=192.168.0.101 LEN=567 TOS=0x00 PREC=0x00 TTL=45 ID=2832 DF PROTO=TCP SPT=80 DPT=59420 WINDOW=7969 RES=0x00 ACK PSH FIN URGP=0 ]
So, the firewall saw it. The question is, what did it do with the traffic. I'll do a search on "invalid" and "iptables".
End Results --
I found the below using "iptables -L" to see if I have blocking of private addresses implemented, to prevent spoofing:
DROP all -- 192.168.0.0/16 anywhere
This was a nice investigation! :-) This is proof that firewall and IDS correlation helps a LOT in investigating strangeness.
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