User talk:LayTek

From Fail2ban
Revision as of 02:47, 10 May 2007 by LayTek (talk | contribs) (filter)
Jump to navigationJump to search

I am running an FTP server (VSFTPD 2.0.5) in a DMZ zone (Shorewall is the firewall running on the gateway computer). I am interested in blocking the script kiddies and dictionary attacks, so I installed Fail2Ban (0.7.6) on the FTP server (Feisty Kubuntu). It doesn't seem to be working though.

My fail2ban.conf looks like this: 


# Fail2Ban configuration file
#
# Author: Cyril Jaquier
#
# $Revision: 494 $
#

[Definition]

# Option:  loglevel
# Notes.:  Set the log level output.
#          1 = ERROR
#          2 = WARN
#          3 = INFO
#          4 = DEBUG
# Values:  NUM  Default:  3
#
loglevel = 3

# Option:  logtarget
# Notes.:  Set the log target. This could be a file, SYSLOG, STDERR or STDOUT.
#          Only one log target can be specified.
# Values:  STDOUT STDERR SYSLOG file  Default:  /var/log/fail2ban.log
#
logtarget = /var/log/fail2ban.log

# Option: socket
# Notes.: Set the socket file. This is used to communicate with the daemon. Do
#         not remove this file when Fail2ban runs. It will not be possible to
#         communicate with the server afterwards.
# Values: FILE  Default:  /tmp/fail2ban.sock
#
socket = /tmp/fail2ban.sock

Nothing special here, so this is my jail.conf: 

# 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 <debian@onerussian.com>
#
# $Revision: 281 $
#

# The DEFAULT allows a global definition of the options. They can be override
# in each jail afterwards.

[DEFAULT]

# "ignoreip" can be an IP address, a CIDR mask or a DNS host
ignoreip = 127.0.0.1
bantime  = 600
maxretry = 3
findtime = 600

# "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 = polling

#
# 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 overriden globally or per 
# section within jail.local file
banaction = iptables-multiport


#
# 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"]

# ban & send an e-mail with whois report to the destemail.
action_mw = %(banaction)s[name=%(__name__)s, port="%(port)s"]
             mail-whois[name=%(__name__)s, dest="%(destemail)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"]
              mail-whois-lines[name=%(__name__)s, dest="%(destemail)s", logpath=%(logpath)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. Please 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,sftp
filter  = sshd
logpath  = /var/log/auth.log
maxretry = 6

[ssh-ddos]

enabled = false
port    = ssh,sftp
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*/*access.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*/*access.log
maxretry  = 6

[apache-noscript]

enabled = false
port    = http,https
filter  = apache-noscript
logpath = /var/log/apache*/*error.log
maxretry = 6

#
# 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

[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
logpath  = /var/log/mail.log

I added "findtime = 600" to this file to get rid of a warning during startup. My jail.local: 

# Fail2Ban local 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
#

[DEFAULT]

# "ignoreip" can be an IP address, a CIDR mask or a DNS host
#ignoreip = 127.0.0.1
#bantime  = 600
#maxretry = 3

#
# JAILS
#

# Next jails corresponds to the standard configuration in Fail2ban 0.6 which
# was shipped in Debian. Please 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

[vsftpd]

enabled  = true
findtime = 600
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 = 5

In this file, I enable vsftpd detection/protection. I then start Fail2Ban, which appears to start normally. 

xxxx@compaq:/etc/fail2ban$ sudo fail2ban-client status
Status
|- Number of jail:      2
`- Jail list:           vsftpd, ssh

As best I can tell, though Fail2Ban is not properly parsing/ detecting the vsftpd.log. Using a loglevel = 4, Fail2Ban reports that the vsftpd.log (and auth.log for ssh) file changes, but it is not picking up on a FAIL LOGIN. Therefore the counters never increment and it never bans an IP.

Help!

filter

What does this line mean? 

# Notes.: regex to match the password failures messages in the logfile. The
#          host must be matched by a group named "host". The tag "<HOST>" can
#          be used for standard IP/hostname matching and is only an alias for
#          (?:::f{4,6}:)?(?P<host>\S+)

This note is in each of the filter definitions.

Am I required to have Linux group named host?

Is this a possilble source of the failure of my filters to capture login failures?

Thanks, LayTek

Retrieved from "http://wiki.fail2ban.org/wiki/index.php?title=User_talk:LayTek&oldid=1891"