一部の人々は、複数のIPアドレスから私のSSHを無差別に代入しようとしました（小さなサンプル）。
May 22 19:50:02 rpi sshd[1272]: pam_unix(sshd:auth): authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=58.218.205.84 user=root
May 22 19:50:04 rpi sshd[1272]: Failed password for root from 58.218.205.84 port 50690 ssh2
May 22 19:50:06 rpi sshd[1272]: Failed password for root from 58.218.205.84 port 50690 ssh2
May 22 19:50:08 rpi sshd[1272]: Failed password for root from 58.218.205.84 port 50690 ssh2
May 22 19:50:09 rpi sshd[1272]: Received disconnect from 58.218.205.84: 11: [preauth]
May 22 19:50:09 rpi sshd[1272]: PAM 2 more authentication failures; logname= uid=0 euid=0 tty=ssh ruser= rhost=58.218.205.84 user=root
May 22 19:50:10 rpi sshd[1276]: pam_unix(sshd:auth): authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=58.218.205.84 user=root
May 22 19:50:13 rpi sshd[1276]: Failed password for root from 58.218.205.84 port 58560 ssh2
May 22 19:50:15 rpi sshd[1276]: Failed password for root from 58.218.205.84 port 58560 ssh2
May 22 19:50:17 rpi sshd[1276]: Failed password for root from 58.218.205.84 port 58560 ssh2
May 22 19:50:18 rpi sshd[1276]: Received disconnect from 58.218.205.84: 11: [preauth]
May 22 19:50:18 rpi sshd[1276]: PAM 2 more authentication failures; logname= uid=0 euid=0 tty=ssh ruser= rhost=58.218.205.84 user=root
May 22 19:50:24 rpi sshd[1280]: pam_unix(sshd:auth): authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=58.218.205.84 user=root
May 22 19:50:27 rpi sshd[1280]: Failed password for root from 58.218.205.84 port 34793 ssh2
May 22 19:50:29 rpi sshd[1280]: Failed password for root from 58.218.205.84 port 34793 ssh2
May 22 19:50:31 rpi sshd[1280]: Failed password for root from 58.218.205.84 port 34793 ssh2
May 22 19:50:31 rpi sshd[1280]: Received disconnect from 58.218.205.84: 11: [preauth]
May 22 19:50:31 rpi sshd[1280]: PAM 2 more authentication failures; logname= uid=0 euid=0 tty=ssh ruser= rhost=58.218.205.84 user=root
だからインストールしましたがfail2banダメですね。構成は次のとおりです。
# Fail2Ban configuration file.
#
# This file was composed for Debian systems from the original one
# provided now under /usr/share/doc/fail2ban/examples/jail.conf
# for additional examples.
#
# To avoid merges during upgrades DO NOT MODIFY THIS FILE
# and rather provide your changes in /etc/fail2ban/jail.local
#
# Author: Yaroslav O. Halchenko <[email protected]>
#
# $Revision$
#
# The DEFAULT allows a global definition of the options. They can be overridden
# in each jail afterwards.
[DEFAULT]
# "ignoreip" can be an IP address, a CIDR mask or a DNS host
ignoreip = 127.0.0.1/8 192.168.1.0/24
bantime = 600
maxretry = 3
# "backend" specifies the backend used to get files modification. Available
# options are "gamin", "polling" and "auto".
# yoh: For some reason Debian shipped python-gamin didn't work as expected
# This issue left ToDo, so polling is default backend for now
backend = auto
#
# Destination email address used solely for the interpolations in
# jail.{conf,local} configuration files.
destemail = root@localhost
#
# ACTIONS
#
# Default banning action (e.g. iptables, iptables-new,
# iptables-multiport, shorewall, etc) It is used to define
# action_* variables. Can be overridden globally or per
# section within jail.local file
banaction = iptables-multiport
# email action. Since 0.8.1 upstream fail2ban uses sendmail
# MTA for the mailing. Change mta configuration parameter to mail
# if you want to revert to conventional 'mail'.
mta = sendmail
# Default protocol
protocol = tcp
# Specify chain where jumps would need to be added in iptables-* actions
chain = INPUT
#
# Action shortcuts. To be used to define action parameter
# The simplest action to take: ban only
action_ = %(banaction)s[name=%(__name__)s, port="%(port)s", protocol="%(protocol)s", chain="%(chain)s"]
# ban & send an e-mail with whois report to the destemail.
action_mw = %(banaction)s[name=%(__name__)s, port="%(port)s", protocol="%(protocol)s", chain="%(chain)s"]
%(mta)s-whois[name=%(__name__)s, dest="%(destemail)s", protocol="%(protocol)s", chain="%(chain)s"]
# ban & send an e-mail with whois report and relevant log lines
# to the destemail.
action_mwl = %(banaction)s[name=%(__name__)s, port="%(port)s", protocol="%(protocol)s", chain="%(chain)s"]
%(mta)s-whois-lines[name=%(__name__)s, dest="%(destemail)s", logpath=%(logpath)s, chain="%(chain)s"]
# Choose default action. To change, just override value of 'action' with the
# interpolation to the chosen action shortcut (e.g. action_mw, action_mwl, etc) in jail.local
# globally (section [DEFAULT]) or per specific section
action = %(action_)s
#
# JAILS
#
# Next jails corresponds to the standard configuration in Fail2ban 0.6 which
# was shipped in Debian. Enable any defined here jail by including
#
# [SECTION_NAME]
# enabled = true
#
# in /etc/fail2ban/jail.local.
#
# Optionally you may override any other parameter (e.g. banaction,
# action, port, logpath, etc) in that section within jail.local
[ssh]
enabled = true
port = ssh
filter = sshd
logpath = /var/log/auth.log
maxretry = 6
[dropbear]
enabled = false
port = ssh
filter = sshd
logpath = /var/log/dropbear
maxretry = 6
# Generic filter for pam. Has to be used with action which bans all ports
# such as iptables-allports, shorewall
[pam-generic]
enabled = false
# pam-generic filter can be customized to monitor specific subset of 'tty's
filter = pam-generic
# port actually must be irrelevant but lets leave it all for some possible uses
port = all
banaction = iptables-allports
port = anyport
logpath = /var/log/auth.log
maxretry = 6
[xinetd-fail]
enabled = false
filter = xinetd-fail
port = all
banaction = iptables-multiport-log
logpath = /var/log/daemon.log
maxretry = 2
[ssh-ddos]
enabled = false
port = ssh
filter = sshd-ddos
logpath = /var/log/auth.log
maxretry = 6
#
# HTTP servers
#
[apache]
enabled = false
port = http,https
filter = apache-auth
logpath = /var/log/apache*/*error.log
maxretry = 6
# default action is now multiport, so apache-multiport jail was left
# for compatibility with previous (<0.7.6-2) releases
[apache-multiport]
enabled = false
port = http,https
filter = apache-auth
logpath = /var/log/apache*/*error.log
maxretry = 6
[apache-noscript]
enabled = false
port = http,https
filter = apache-noscript
logpath = /var/log/apache*/*error.log
maxretry = 6
[apache-overflows]
enabled = false
port = http,https
filter = apache-overflows
logpath = /var/log/apache*/*error.log
maxretry = 2
#
# FTP servers
#
[vsftpd]
enabled = false
port = ftp,ftp-data,ftps,ftps-data
filter = vsftpd
logpath = /var/log/vsftpd.log
# or overwrite it in jails.local to be
# logpath = /var/log/auth.log
# if you want to rely on PAM failed login attempts
# vsftpd's failregex should match both of those formats
maxretry = 6
[proftpd]
enabled = false
port = ftp,ftp-data,ftps,ftps-data
filter = proftpd
logpath = /var/log/proftpd/proftpd.log
maxretry = 6
[pure-ftpd]
enabled = false
port = ftp,ftp-data,ftps,ftps-data
filter = pure-ftpd
logpath = /var/log/auth.log
maxretry = 6
[wuftpd]
enabled = false
port = ftp,ftp-data,ftps,ftps-data
filter = wuftpd
logpath = /var/log/auth.log
maxretry = 6
#
# Mail servers
#
[postfix]
enabled = false
port = smtp,ssmtp
filter = postfix
logpath = /var/log/mail.log
[couriersmtp]
enabled = false
port = smtp,ssmtp
filter = couriersmtp
logpath = /var/log/mail.log
#
# Mail servers authenticators: might be used for smtp,ftp,imap servers, so
# all relevant ports get banned
#
[courierauth]
enabled = false
port = smtp,ssmtp,imap2,imap3,imaps,pop3,pop3s
filter = courierlogin
logpath = /var/log/mail.log
[sasl]
enabled = false
port = smtp,ssmtp,imap2,imap3,imaps,pop3,pop3s
filter = sasl
# You might consider monitoring /var/log/mail.warn instead if you are
# running postfix since it would provide the same log lines at the
# "warn" level but overall at the smaller filesize.
logpath = /var/log/mail.log
[dovecot]
enabled = false
port = smtp,ssmtp,imap2,imap3,imaps,pop3,pop3s
filter = dovecot
logpath = /var/log/mail.log
# DNS Servers
# These jails block attacks against named (bind9). By default, logging is off
# with bind9 installation. You will need something like this:
#
# logging {
# channel security_file {
# file "/var/log/named/security.log" versions 3 size 30m;
# severity dynamic;
# print-time yes;
# };
# category security {
# security_file;
# };
# };
#
# in your named.conf to provide proper logging
# !!! WARNING !!!
# Since UDP is connection-less protocol, spoofing of IP and imitation
# of illegal actions is way too simple. Thus enabling of this filter
# might provide an easy way for implementing a DoS against a chosen
# victim. See
# http://nion.modprobe.de/blog/archives/690-fail2ban-+-dns-fail.html
# Please DO NOT USE this jail unless you know what you are doing.
#[named-refused-udp]
#
#enabled = false
#port = domain,953
#protocol = udp
#filter = named-refused
#logpath = /var/log/named/security.log
[named-refused-tcp]
enabled = false
port = domain,953
protocol = tcp
filter = named-refused
logpath = /var/log/named/security.log
無視する必要があるローカルIPを除いて、内部では何も変更しませんでした。したがって、今日4000回のログイン試行後も、そのIPは一度もブロックされませんでした。ログには、ユーザーがまだ毎分何度も再試行できることが明らかになっているからです。
だから私はsudo iptables -L次のような結果を得ました。
libkmod: ERROR ../libkmod/libkmod.c:554 kmod_search_moddep: could not open moddep file '/lib/modules/3.18.7-v7+/modules.dep.bin'
iptables v1.4.14: can't initialize iptables table `filter': Table does not exist (do you need to insmod?)
Perhaps iptables or your kernel needs to be upgraded.
よく。また、Fail2banログを確認して、次のようにしcat /var/log/fail2ban.logました。
2015-05-22 12:05:43,083 fail2ban.server : INFO Changed logging target to /var/log/fail2ban.log for Fail2ban v0.8.6
2015-05-22 12:05:43,086 fail2ban.jail : INFO Creating new jail 'ssh'
2015-05-22 12:05:43,088 fail2ban.jail : INFO Jail 'ssh' uses poller
2015-05-22 12:05:43,166 fail2ban.filter : INFO Added logfile = /var/log/auth.log
2015-05-22 12:05:43,169 fail2ban.filter : INFO Set maxRetry = 6
2015-05-22 12:05:43,173 fail2ban.filter : INFO Set findtime = 600
2015-05-22 12:05:43,176 fail2ban.actions: INFO Set banTime = 600
2015-05-22 12:05:43,385 fail2ban.jail : INFO Jail 'ssh' started
2015-05-22 12:05:43,467 fail2ban.actions.action: ERROR iptables -N fail2ban-ssh
iptables -A fail2ban-ssh -j RETURN
iptables -I INPUT -p tcp -m multiport --dports ssh -j fail2ban-ssh returned 300
2015-05-22 19:42:34,799 fail2ban.server : INFO Stopping all jails
2015-05-22 19:42:35,753 fail2ban.actions.action: ERROR iptables -D INPUT -p tcp -m multiport --dports ssh -j fail2ban-ssh
iptables -F fail2ban-ssh
iptables -X fail2ban-ssh returned 300
2015-05-22 19:42:35,754 fail2ban.jail : INFO Jail 'ssh' stopped
2015-05-22 19:42:35,763 fail2ban.server : INFO Exiting Fail2ban
2015-05-22 19:42:37,686 fail2ban.server : INFO Changed logging target to /var/log/fail2ban.log for Fail2ban v0.8.6
2015-05-22 19:42:37,689 fail2ban.jail : INFO Creating new jail 'ssh'
2015-05-22 19:42:37,695 fail2ban.jail : INFO Jail 'ssh' uses Gamin
2015-05-22 19:42:37,824 fail2ban.filter : INFO Added logfile = /var/log/auth.log
2015-05-22 19:42:37,827 fail2ban.filter : INFO Set maxRetry = 6
2015-05-22 19:42:37,834 fail2ban.filter : INFO Set findtime = 600
2015-05-22 19:42:37,837 fail2ban.actions: INFO Set banTime = 600
2015-05-22 19:42:38,053 fail2ban.jail : INFO Jail 'ssh' started
2015-05-22 19:42:38,126 fail2ban.actions.action: ERROR iptables -N fail2ban-ssh
iptables -A fail2ban-ssh -j RETURN
iptables -I INPUT -p tcp -m multiport --dports ssh -j fail2ban-ssh returned 300
fail2ban-regex私も確認してauth.logみると4000個を超える一致項目があると言いましたね。
何が起こったのか、raspianでiptablesが壊れていますか？どうすれば修正できますか？
答え1
解決策が見つかりました。以下を実行してください。
sudo rpi-update
iptablesファームウェア、カーネルバージョン、および動作に必要なその他の事項を更新しましたfail2ban。