• Re: Unwanted connections to port 23.

    From Jon Watson@1:249/207 to Ignatius on Thu Aug 10 12:37:12 2017
    Hi,

    I've tried Janis' iptables suggestion, but it isn't working.

    What didn't work about it? Seems the only real variable in there is the nic (eth0 in Janis' example).

    --- Mystic BBS v1.10 (Linux)
    * Origin: TheHeartOfGoldBBS.ca (1:249/207)
  • From Fernando Toledo@4:902/26 to Ignatius on Thu Sep 7 10:39:36 2017
    El 11/06/17 a las 21:54, Ignatius escribió:
    I've since recently put my board back on port 23... and I now recall why I took it off of it. I keep getting all of these connections from hackers, I take it. Anyone know of a way to filter these bad connections?

    I've tried Janis' iptables suggestion, but it isn't working.

    Thanks,
    Joseph



    try fail2ban
    --- SBBSecho 3.01-Linux
    * Origin: Dock Sud BBS - http://bbs.docksud.com.ar (4:902/26)
  • From Janis Kracht@1:261/38 to Ignatius on Tue Oct 24 13:06:34 2017
    Hi Joseph,

    I've since recently put my board back on port 23... and I now recall why I took it off of it. I keep getting all of these connections from hackers, I take it. Anyone know of a way to filter these bad connections?

    I've tried Janis' iptables suggestion, but it isn't working.

    The first thing I do after a reboot (which happens rarely) is turn off iptables
    since ubuntu starts if right off the bat everytime automatically:

    iptables -F
    iptables -X

    The above two commands do that. Once I've turned it off, I restart it with my own parameters in the two lines below:

    For my web server which I run on port 8080:

    1)sudo iptables -I INPUT -p tcp --dport 8080 -i eth0 -m state --state NEW -m recent --set [all on one line]

    2)sudo iptables -I INPUT -p tcp --dport 8080 -i eth0 -m state --state NEW -m recent --update --seconds 60 --hitcount 2 -j DROP [all on one line]

    I could use the same commands for my telnet server which runs on port 2030, so to include the telnet port I would change "dport 8080" with dport 2030 in the lines above. If you are using port 23, you would change dport to 23 above.

    Finally, I issue the command:
    sudo iptables -L
    to check that I've got the iptables command that I want:

    bbs@filegate:~$ sudo iptables -L
    Chain INPUT (policy ACCEPT)
    target prot opt source destination
    DROP tcp -- anywhere anywhere tcp dpt:http-alt state NEW recent: UPDATE seconds: 60 hit_count: 2 name: DEFAULT side: source
    tcp -- anywhere anywhere tcp
    dpt:http-alt state NEW recent: SET name: DEFAULT side: source

    Chain FORWARD (policy DROP)
    target prot opt source destination

    Chain OUTPUT (policy ACCEPT)
    target prot opt source destination

    The above two commands keep jokers from killing my servers after two connections in 60 seconds :)

    Hope this helps,
    Janis

    --- BBBS/Li6 v4.10 Toy-3
    * Origin: Prism bbs (1:261/38)
  • From Janis Kracht@1:261/38 to Ignatious on Tue Oct 24 13:20:36 2017
    Hi,

    I've since recently put my board back on port 23... and I now recall why I took it off of it. I keep getting all of these connections from hackers, I take it. Anyone know of a way to filter these bad connections?

    I've tried Janis' iptables suggestion, but it isn't working.

    The first thing I do after a reboot (which happens rarely) is turn off iptables
    since ubuntu starts if right off the bat everytime automatically:

    iptables -F
    iptables -X

    The above two commands do that. Once I've turned it off, I restart it with my own parameters in the two lines below:

    For my web server which I run on port 8080:

    1)sudo iptables -I INPUT -p tcp --dport 8080 -i eth0 -m state --state NEW -m recent --set [all on one line]

    2)sudo iptables -I INPUT -p tcp --dport 8080 -i eth0 -m state --state NEW -m recent --update --seconds 60 --hitcount 2 -j DROP [all on one line]

    I could use the same commands for my telnet server which runs on port 2030, so to include the telnet port I would change "dport 8080" with dport 2030 in the lines above. If you are using port 23, you would change dport to 23 above.

    Finally, I issue the command:
    sudo iptables -L
    to check that I've got the iptables command that I want:

    bbs@filegate:~$ sudo iptables -L
    Chain INPUT (policy ACCEPT)
    target prot opt source destination
    DROP tcp -- anywhere anywhere tcp dpt:http-alt state NEW recent: UPDATE seconds: 60 hit_count: 2 name: DEFAULT side: source
    tcp -- anywhere anywhere tcp
    dpt:http-alt state NEW recent: SET name: DEFAULT side: source

    Chain FORWARD (policy DROP)
    target prot opt source destination

    Chain OUTPUT (policy ACCEPT)
    target prot opt source destination

    The above two commands keep jokers from killing my servers after two connections in 60 seconds :)

    Hope this helps,
    Janis

    --- BBBS/Li6 v4.10 Toy-3
    * Origin: Prism bbs (1:261/38)
  • From Phil Kimble@1:128/2 to Janis Kracht on Sun Oct 29 10:21:20 2017
    I've since recently put my board back on port 23... and I now recall
    why I took it off of it. I keep getting all of these connections from
    hackers, I take it. Anyone know of a way to filter these bad
    connections?

    I've tried Janis' iptables suggestion, but it isn't working.

    Have a look at fail2ban www.fail2ban.org claims to be a "poor man's ids".

    I installed it from the yum repos on CentOS7 & configured it for 3 attempts.
    If you fail to login for 3 attempts you are banned for 15 minutes. All activity is logged. Luckily I was smart enough to setup several local accounts <Thx Janis>
    so when I forget the admin password I was still able to reset the timer for that
    acount via sudo...

    I like it lots!



    --- Msged/LNX 6.1.2
    * Origin: Bayhaus.net - Colorado Springs - Serving the FrontRange (1:128/2)
  • From Janis Kracht@1:261/38 to Phil Kimble on Thu Nov 2 14:02:56 2017
    Hi Phil!

    I've tried Janis' iptables suggestion, but it isn't working.

    Have a look at fail2ban www.fail2ban.org claims to be a "poor man's ids".

    Nah, my system is fine using iptables. IIRC fail2ban uses iptables, right?

    I installed it from the yum repos on CentOS7 & configured it for 3 attempts.
    If you fail to login for 3 attempts you are banned for 15 minutes. All activit
    is logged. Luckily I was smart enough to setup several local accounts <Thx Janis>
    so when I forget the admin password I was still able to reset the timer for that
    acount via sudo...

    I like it lots!

    Great :)

    Take care,
    Janis

    --- BBBS/Li6 v4.10 Toy-3
    * Origin: Prism bbs (1:261/38)
  • From Richard Menedetter@2:310/31 to Janis Kracht on Thu Nov 2 20:13:42 2017
    Hi Janis!

    02 Nov 2017 14:02, from Janis Kracht -> Phil Kimble:

    Have a look at fail2ban www.fail2ban.org claims to be a "poor man's
    ids".
    Nah, my system is fine using iptables. IIRC fail2ban uses iptables,
    right?

    Yes.
    It can issue any command, but in the default config it will block via iptables.

    CU, Ricsi

    --- GoldED+/LNX
    * Origin: The Boy Scouts have adult leadership. The Army doesn't. (2:310/31)