Centos

fail2ban iptables 具有埠 22 並且無法阻止自定義埠上的 ssh

  • July 31, 2013

這個問題與我的問題幾乎相同,但接受的答案並不能解決我的問題

在 Fail2Ban 中,如何更改 SSH 埠號?

埠 22 上的 SSH 一切正常。在 5 次嘗試後,fail2ban 從日誌中讀取並禁止我的 ip 600 秒。這是fail2ban日誌

2013-07-10 11:54:08,522 fail2ban.actions: WARNING [ssh-iptables] Ban 192.168.162.191
2013-07-10 12:04:09,348 fail2ban.actions: WARNING [ssh-iptables] Unban 192.168.162.191

我的 iptables,fail2ban 有埠 22

Chain INPUT (policy ACCEPT 1591 packets, 165K bytes)
pkts bytes target     prot opt in     out     source               destination
  44  5292 fail2ban-SSH  tcp  --  *      *       0.0.0.0/0            0.0.0.0/0           tcp dpt:22

Chain FORWARD (policy ACCEPT 0 packets, 0 bytes)
pkts bytes target     prot opt in     out     source               destination

Chain OUTPUT (policy ACCEPT 181 packets, 71152 bytes)
pkts bytes target     prot opt in     out     source               destination

Chain fail2ban-SSH (1 references)
pkts bytes target     prot opt in     out     source               destination
  35  4836 RETURN     all  --  *      *       0.0.0.0/0            0.0.0.0/0

我通過編輯 ssh 配置將 SSH 埠更改為 12345

vi /etc/ssh/sshd_config
service sshd restart

現在 ssh 在埠 12345 而不是 22 上工作,完全沒問題

日誌正確顯示我失敗的登錄嘗試

5 次嘗試後,fail2ban 日誌文件顯示禁令

2013-07-10 11:37:33,124 fail2ban.actions: WARNING [ssh-iptables] Ban 192.168.162.191

問題是

但它從未禁止我使用 SSH 埠 12345,我仍然可以訪問 ssh 並登錄

我相信這是因為 iptables 在埠 22 上有 fail2ban 規則,但不知道如何編輯它。因為如果我重新啟動 fail2ban,它會再次使用埠 22 添加它自己的規則

編輯1:

監獄.conf

# Fail2Ban jail specifications file
#
# Comments: use '#' for comment lines and ';' (following a space) for inline comments
#
# Changes:  in most of the cases you should not modify this
#           file, but provide customizations in jail.local file, e.g.:
#
# [DEFAULT]
# bantime = 3600
#
# [ssh-iptables]
# enabled = true
#

# 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. Fail2ban will not
# ban a host which matches an address in this list. Several addresses can be
# defined using space separator.
ignoreip = 127.0.0.1/8

# "bantime" is the number of seconds that a host is banned.
bantime  = 600

# A host is banned if it has generated "maxretry" during the last "findtime"
# seconds.
findtime  = 600

# "maxretry" is the number of failures before a host get banned.
maxretry = 3

# "backend" specifies the backend used to get files modification.
# Available options are "pyinotify", "gamin", "polling" and "auto".
# This option can be overridden in each jail as well.
#
# pyinotify: requires pyinotify (a file alteration monitor) to be installed.
#              If pyinotify is not installed, Fail2ban will use auto.
# gamin:     requires Gamin (a file alteration monitor) to be installed.
#              If Gamin is not installed, Fail2ban will use auto.
# polling:   uses a polling algorithm which does not require external libraries.
# auto:      will try to use the following backends, in order:
#              pyinotify, gamin, polling.
backend = auto

# "usedns" specifies if jails should trust hostnames in logs,
#   warn when DNS lookups are performed, or ignore all hostnames in logs
#
# yes:   if a hostname is encountered, a DNS lookup will be performed.
# warn:  if a hostname is encountered, a DNS lookup will be performed,
#        but it will be logged as a warning.
# no:    if a hostname is encountered, will not be used for banning,
#        but it will be logged as info.
usedns = warn


# This jail corresponds to the standard configuration in Fail2ban 0.6.
# The mail-whois action send a notification e-mail with a whois request
# in the body.

[ssh-iptables]

enabled  = true
filter   = sshd
port     = ssh #TRIED TO PUT HERE 12345 port number but problem persists
action   = iptables[name=SSH, port=ssh, protocol=tcp]
          sendmail-whois[name=SSH, dest=root, sender=fail2ban@example.com]
logpath  = /var/log/secure
maxretry = 5

[proftpd-iptables]

enabled  = false
filter   = proftpd
action   = iptables[name=ProFTPD, port=ftp, protocol=tcp]
          sendmail-whois[name=ProFTPD, dest=you@example.com]
logpath  = /var/log/proftpd/proftpd.log
maxretry = 6

# This jail forces the backend to "polling".

[sasl-iptables]

enabled  = false
filter   = sasl
backend  = polling
action   = iptables[name=sasl, port=smtp, protocol=tcp]
          sendmail-whois[name=sasl, dest=you@example.com]
logpath  = /var/log/mail.log

# ASSP SMTP Proxy Jail
[assp]
enabled  = false
filter   = assp
action = iptables-multiport[name=assp,port="25,465,587"]
logpath  = /root/path/to/assp/logs/maillog.txt

# Here we use TCP-Wrappers instead of Netfilter/Iptables. "ignoreregex" is
# used to avoid banning the user "myuser".

[ssh-tcpwrapper]

enabled     = false
filter      = sshd
action      = hostsdeny
             sendmail-whois[name=SSH, dest=you@example.com]
ignoreregex = for myuser from
logpath     = /var/log/sshd.log

# Here we use blackhole routes for not requiring any additional kernel support
# to store large volumes of banned IPs

[ssh-route]

enabled = false
filter = sshd
action = route
logpath = /var/log/sshd.log
maxretry = 5

# Here we use a combination of Netfilter/Iptables and IPsets
# for storing large volumes of banned IPs
#
# IPset comes in two versions. See ipset -V for which one to use
# requires the ipset package and kernel support.
[ssh-iptables-ipset4]

enabled  = false
filter   = sshd
action   = iptables-ipset-proto4[name=SSH, port=ssh, protocol=tcp]
logpath  = /var/log/sshd.log
maxretry = 5

[ssh-iptables-ipset6]
enabled  = false
filter   = sshd
action   = iptables-ipset-proto6[name=SSH, port=ssh, protocol=tcp, bantime=600]
logpath  = /var/log/sshd.log
maxretry = 5

# bsd-ipfw is ipfw used by BSD. It uses ipfw tables.
# table number must be unique.
# 
# This will create a deny rule for that table ONLY if a rule 
# for the table doesn't ready exist.
#
[ssh-bsd-ipfw]
enabled  = false
filter   = sshd
action   = bsd-ipfw[port=ssh,table=1]
logpath  = /var/log/auth.log
maxretry = 5

# This jail demonstrates the use of wildcards in "logpath".
# Moreover, it is possible to give other files on a new line.

[apache-tcpwrapper]

enabled  = false
filter   = apache-auth
action   = hostsdeny
logpath  = /var/log/apache*/*error.log
          /home/www/myhomepage/error.log
maxretry = 6

# The hosts.deny path can be defined with the "file" argument if it is
# not in /etc.

[postfix-tcpwrapper]

enabled  = false
filter   = postfix
action   = hostsdeny[file=/not/a/standard/path/hosts.deny]
          sendmail[name=Postfix, dest=you@example.com]
logpath  = /var/log/postfix.log
bantime  = 300

# Do not ban anybody. Just report information about the remote host.
# A notification is sent at most every 600 seconds (bantime).

[vsftpd-notification]

enabled  = false
filter   = vsftpd
action   = sendmail-whois[name=VSFTPD, dest=you@example.com]
logpath  = /var/log/vsftpd.log
maxretry = 5
bantime  = 1800

# Same as above but with banning the IP address.

[vsftpd-iptables]

enabled  = false
filter   = vsftpd
action   = iptables[name=VSFTPD, port=ftp, protocol=tcp]
          sendmail-whois[name=VSFTPD, dest=you@example.com]
logpath  = /var/log/vsftpd.log
maxretry = 5
bantime  = 1800

# Ban hosts which agent identifies spammer robots crawling the web
# for email addresses. The mail outputs are buffered.

[apache-badbots]

enabled  = false
filter   = apache-badbots
action   = iptables-multiport[name=BadBots, port="http,https"]
          sendmail-buffered[name=BadBots, lines=5, dest=you@example.com]
logpath  = /var/www/*/logs/access_log
bantime  = 172800
maxretry = 1

# Use shorewall instead of iptables.

[apache-shorewall]

enabled  = false
filter   = apache-noscript
action   = shorewall
          sendmail[name=Postfix, dest=you@example.com]
logpath  = /var/log/apache2/error_log

# Monitor roundcube server

[roundcube-iptables]

enabled  = false
filter   = roundcube-auth
action   = iptables[name=RoundCube, port="http,https"]
logpath  = /var/log/roundcube/userlogins


# Monitor SOGo groupware server

[sogo-iptables]

enabled  = false
filter   = sogo-auth
# without proxy this would be:
# port    = 20000
action   = iptables[name=SOGo, port="http,https"]
logpath  = /var/log/sogo/sogo.log

# Ban attackers that try to use PHP's URL-fopen() functionality
# through GET/POST variables. - Experimental, with more than a year
# of usage in production environments.

[php-url-fopen]

enabled = false
action  = iptables[name=php-url-open, port="http,https"]
filter  = php-url-fopen
logpath = /var/www/*/logs/access_log
maxretry = 1

# A simple PHP-fastcgi jail which works with lighttpd.
# If you run a lighttpd server, then you probably will
# find these kinds of messages in your error_log:
# ALERT – tried to register forbidden variable ‘GLOBALS’
# through GET variables (attacker '1.2.3.4', file '/var/www/default/htdocs/index.php')
# This jail would block the IP 1.2.3.4.

[lighttpd-fastcgi]

enabled = false
filter  = lighttpd-fastcgi
action  = iptables[name=lighttpd-fastcgi, port="http,https"]
# adapt the following two items as needed
logpath = /var/log/lighttpd/error.log
maxretry = 2

# Same as above for mod_auth
# It catches wrong authentications

[lighttpd-auth]

enabled = false
filter  = lighttpd-auth
action  = iptables[name=lighttpd-auth, port="http,https"]
# adapt the following two items as needed
logpath = /var/log/lighttpd/error.log
maxretry = 2

# This jail uses ipfw, the standard firewall on FreeBSD. The "ignoreip"
# option is overridden in this jail. Moreover, the action "mail-whois" defines
# the variable "name" which contains a comma using "". The characters '' are
# valid too.

[ssh-ipfw]

enabled  = false
filter   = sshd
action   = ipfw[localhost=192.168.0.1]
          sendmail-whois[name="SSH,IPFW", dest=you@example.com]
logpath  = /var/log/auth.log
ignoreip = 168.192.0.1

# 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.
# This jail blocks UDP traffic for DNS requests.

# !!! 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
# filter   = named-refused
# action   = iptables-multiport[name=Named, port="domain,953", protocol=udp]
#            sendmail-whois[name=Named, dest=you@example.com]
# logpath  = /var/log/named/security.log
# ignoreip = 168.192.0.1

# This jail blocks TCP traffic for DNS requests.

[named-refused-tcp]

enabled  = false
filter   = named-refused
action   = iptables-multiport[name=Named, port="domain,953", protocol=tcp]
          sendmail-whois[name=Named, dest=you@example.com]
logpath  = /var/log/named/security.log
ignoreip = 168.192.0.1

# Multiple jails, 1 per protocol, are necessary ATM:
# see https://github.com/fail2ban/fail2ban/issues/37
[asterisk-tcp]

enabled  = false
filter   = asterisk
action   = iptables-multiport[name=asterisk-tcp, port="5060,5061", protocol=tcp]
          sendmail-whois[name=Asterisk, dest=you@example.com, sender=fail2ban@example.com]
logpath  = /var/log/asterisk/messages
maxretry = 10

[asterisk-udp]

enabled  = false
filter   = asterisk
action   = iptables-multiport[name=asterisk-udp, port="5060,5061", protocol=udp]
          sendmail-whois[name=Asterisk, dest=you@example.com, sender=fail2ban@example.com]
logpath  = /var/log/asterisk/messages
maxretry = 10

# To log wrong MySQL access attempts add to /etc/my.cnf:
# log-error=/var/log/mysqld.log
# log-warning = 2
[mysqld-iptables]

enabled  = false
filter   = mysqld-auth
action   = iptables[name=mysql, port=3306, protocol=tcp]
          sendmail-whois[name=MySQL, dest=root, sender=fail2ban@example.com]
logpath  = /var/log/mysqld.log
maxretry = 5


# Jail for more extended banning of persistent abusers
# !!! WARNING !!!
#   Make sure that your loglevel specified in fail2ban.conf/.local
#   is not at DEBUG level -- which might then cause fail2ban to fall into
#   an infinite loop constantly feeding itself with non-informative lines
[recidive]

enabled  = false
filter   = recidive
logpath  = /var/log/fail2ban.log
action   = iptables-allports[name=recidive]
          sendmail-whois-lines[name=recidive, logpath=/var/log/fail2ban.log]
bantime  = 604800  ; 1 week
findtime = 86400   ; 1 day
maxretry = 5

# PF is a BSD based firewall
[ssh-pf]

enabled=false
filter = sshd
action = pf
logpath  = /var/log/sshd.log
maxretry=5

由於您使用 ssh 作為埠名稱,因此它將搜尋 /etc/services 文件並將名稱映射ssh到關聯的埠,即22

您可以簡單地修改/etc/services文件並將埠更改22/tcp為您喜歡的任何內容。

保存更改,您就完成了!

您必須更改該action行中的預設埠,如下所示:

[ssh-iptables]

enabled  = true
filter   = sshd
action   = iptables[name=SSH, port=12345, protocol=tcp]
          sendmail-whois[name=SSH, dest=root, sender=fail2ban@example.com]
logpath  = /var/log/secure
maxretry = 5

之後不要忘記重新啟動fail2ban。

引用自:https://serverfault.com/questions/522191