Fail2Ban not banning IPs with different ports

fail2ban

I am getting different SSH attacks from the same IPs and they are getting banned. But they are using a different port and all they have to do is change the port to bypass the ban.

Dec 28 23:16:57 Nixie sshd[30706]: Failed password for root from 40.127.178.38 port 3424 ssh2
Dec 28 23:16:54 Nixie sshd[30704]: Failed password for root from 40.127.178.38 port 1112 ssh2
Dec 28 23:16:51 Nixie sshd[30702]: Failed password for root from 40.127.178.38 port 1116 ssh2
Dec 28 23:16:47 Nixie sshd[30700]: Failed password for root from 40.127.178.38 port 1115 ssh2
Dec 28 23:16:43 Nixie sshd[30698]: Failed password for root from 40.127.178.38 port 1114 ssh2
Dec 28 23:16:40 Nixie sshd[30696]: Failed password for root from 40.127.178.38 port 1113 ssh2
Dec 28 23:16:37 Nixie sshd[30694]: Failed password for root from 40.127.178.38 port 3424 ssh2
Dec 28 23:16:33 Nixie sshd[30692]: Failed password for root from 40.127.178.38 port 1112 ssh2

Here is my jail.local:

   # 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.    
#    
# Comments: use '#' for comment lines and ';' for inline comments    
#    
# To avoid merges during upgrades DO NOT MODIFY THIS FILE    
# and rather provide your changes in /etc/fail2ban/jail.local    
#    

# 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  = 3600    

# A host is banned if it has generated "maxretry" during the last "findtime"    
# seconds.    
findtime = 600    
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 reverse DNS lookups are performed, or ignore all hostnames in logs    
#    
# yes:   if a hostname is encountered, a reverse DNS lookup will be performed.    
# warn:  if a hostname is encountered, a reverse 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    

#    
# Destination email address used solely for the interpolations in    
# jail.{conf,local} configuration files.    
destemail = root@localhost    

#    
# Name of the sender for mta actions    
sendername = Fail2Ban    

#    
# 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-allports    

# 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", sendername="%(sendername)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", sendername="%(sendername)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 = 3    

[dropbear]    

enabled  = false    
port     = ssh    
filter   = dropbear    
logpath  = /var/log/auth.log    
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    


# 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 = 6    

# 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    
port     = ssh    
filter   = sshd    
banaction = iptables-ipset-proto4    
logpath  = /var/log/sshd.log    
maxretry = 6    

[ssh-iptables-ipset6]    

enabled  = false    
port     = ssh    
filter   = sshd    
banaction = iptables-ipset-proto6    
logpath  = /var/log/sshd.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    

# 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    
port    = http,https    
filter  = php-url-fopen    
logpath = /var/www/*/logs/access_log    

# 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')    

[lighttpd-fastcgi]    

enabled = false    
port    = http,https    
filter  = lighttpd-fastcgi    
logpath = /var/log/lighttpd/error.log    

# Same as above for mod_auth    
# It catches wrong authentifications    

[lighttpd-auth]    

enabled = false    
port    = http,https    
filter  = suhosin    
logpath = /var/log/lighttpd/error.log    

[nginx-http-auth]    

enabled = true    
filter  = nginx-http-auth    
port    = http,https    
logpath = /var/log/nginx/error.log    

# Monitor roundcube server    

[roundcube-auth]    

enabled  = false    
filter   = roundcube-auth    
port     = http,https    
logpath  = /var/log/roundcube/userlogins    


[sogo-auth]    

enabled  = false    
filter   = sogo-auth    
port     = http, https    
# without proxy this would be:    
# port    = 20000    
logpath  = /var/log/sogo/sogo.log    


#    
# 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/syslog    
maxretry = 6    


[wuftpd]    

enabled  = false    
port     = ftp,ftp-data,ftps,ftps-data    
filter   = wuftpd    
logpath  = /var/log/syslog    
maxretry = 6    


#    
# Mail servers    
#    

[postfix]    

enabled  = false    
port     = smtp,ssmtp,submission    
filter   = postfix    
logpath  = /var/log/mail.log    


[couriersmtp]    

enabled  = false    
port     = smtp,ssmtp,submission    
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,submission,imap2,imap3,imaps,pop3,pop3s    
filter   = courierlogin    
logpath  = /var/log/mail.log    


[sasl]    

enabled  = false    
port     = smtp,ssmtp,submission,imap2,imap3,imaps,pop3,pop3s    
filter   = postfix-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,submission,imap2,imap3,imaps,pop3,pop3s    
filter  = dovecot    
logpath = /var/log/mail.log    

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

enabled  = false    
filter   = mysqld-auth    
port     = 3306    
logpath  = /var/log/mysqld.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    

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

enabled  = false    
filter   = asterisk    
port     = 5060,5061    
protocol = tcp    
logpath  = /var/log/asterisk/messages    

[asterisk-udp]    

enabled  = false    
filter   = asterisk    
port     = 5060,5061    
protocol = udp    
logpath  = /var/log/asterisk/messages    


# 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    

Why aren't the IPs being blocked?

Here is my filter.d/sshd.conf

# Fail2Ban filter for openssh
#

[INCLUDES]

# Read common prefixes. If any customizations available -- read them from
# common.local
before = common.conf


[Definition]

_daemon = sshd

failregex = ^%(__prefix_line)s(?:error: PAM: )?[aA]uthentication (?:failure|error) for .* from <HOST>( via \S+)?\s*$
            ^%(__prefix_line)s(?:error: PAM: )?User not known to the underlying authentication module for .* from <HOST>\s*$
            ^%(__prefix_line)sFailed \S+ for .*? from <HOST>(?: port \d*)?(?: ssh\d*)?(: (ruser .*|(\S+ ID \S+ \(serial \d+\) CA )?\S+ %(__md5hex)s(, client user ".*", client host ".*")?))?\s*$
            ^%(__prefix_line)sROOT LOGIN REFUSED.* FROM <HOST>\s*$
            ^%(__prefix_line)s[iI](?:llegal|nvalid) user .* from <HOST>\s*$
            ^%(__prefix_line)sUser .+ from <HOST> not allowed because not listed in AllowUsers\s*$
            ^%(__prefix_line)sUser .+ from <HOST> not allowed because listed in DenyUsers\s*$
            ^%(__prefix_line)sUser .+ from <HOST> not allowed because not in any group\s*$
            ^%(__prefix_line)srefused connect from \S+ \(<HOST>\)\s*$
            ^%(__prefix_line)sUser .+ from <HOST> not allowed because a group is listed in DenyGroups\s*$
            ^%(__prefix_line)sUser .+ from <HOST> not allowed because none of user's groups are listed in AllowGroups\s*$

ignoreregex = 

# DEV Notes:
#
#   "Failed \S+ for .*? from <HOST>..." failregex uses non-greedy catch-all because
#   it is coming before use of <HOST> which is not hard-anchored at the end as well,
#   and later catch-all's could contain user-provided input, which need to be greedily
#   matched away first.
#
# Author: Cyril Jaquier, Yaroslav Halchenko, Petr Voralek, Daniel Black

Output of iptables -L

Chain INPUT (policy ACCEPT)
target     prot opt source               destination         
DROP       all  --  43.229.53.66         anywhere            
DROP       all  --  58.218.211.38        anywhere            
DROP       all  --  124.173.68.198       anywhere            
DROP       all  --  183.56.173.20        anywhere            

Chain FORWARD (policy ACCEPT)
target     prot opt source               destination         

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination  

Best Answer

It is quite possible that the sshd.filter does not match the lines you have. The filter I have installed would not match those lines. There is a fail2ban-regex utility that can be used to test your regex. A multi-line string in the regex contains multiple regexes, one per line.

A regex like the following may match better. I think the existing regex is not finding enough data.

^%(__prefix_line)sFailed \S+ for .*? from <HOST>(?: port \d*)?(?: ssh\d*)?

When testing you may have to define things like __prefix_line in the test script. Then try matching some records extracted from your log file.

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