메뉴 건너뛰기

DDART.NET

2019.06.11 00:45

Fail2Ban 설정하기

조회 수 470 추천 수 0 댓글 0
?

단축키

Prev이전 문서

Next다음 문서

크게 작게 위로 아래로 댓글로 가기 인쇄
?

단축키

Prev이전 문서

Next다음 문서

크게 작게 위로 아래로 댓글로 가기 인쇄

0. 설치

 

$ apt install fail2ban

 

vi /etc/fail2ban/jail.conf

# "ignoreip" can be a list of IP addresses, CIDR masks or DNS hosts. Fail2ban
# will not ban a host which matches an address in this list. Several addresses
# can be defined using space (and/or comma) separator.
ignoreip = 127.0.0.1/8 ::1 192.168.0.1/16 관리자IP주소대역/8

# External command that will take an tagged arguments to ignore, e.g. <ip>,
# and return true if the IP is to be ignored. False otherwise.
#
# ignorecommand = /path/to/command <ip>
ignorecommand =

# "bantime" is the number of seconds that a host is banned.
bantime  = 86400

 

 

1. DB초기화

 

service fail2ban stop
sqlite3 /var/lib/fail2ban/fail2ban.sqlite3 "delete from bans;"
sqlite3 /var/lib/fail2ban/fail2ban.sqlite3 "delete from jails;"

 

 

2. vi /etc/fail2ban/jail.d/defaults-debian.conf

 

[sshd]
enabled = true
maxretry = 1

[postfix-sasl]
enabled = true
port = smtp
maxretry = 1

[vsftpd]
enabled = true
port = ftp
maxretry = 1

 

 

3. /etc/fail2ban/action.d/iptables-multiport.conf

 

필터에 걸리면 그 아이피 대역대 24bit mask 로 drop 시켜버리기

 

# Fail2Ban configuration file
#
# Author: Cyril Jaquier
# Modified by Yaroslav Halchenko for multiport banning
#

[INCLUDES]

before = iptables-common.conf

[Definition]

# Option:  actionstart
# Notes.:  command executed once at the start of Fail2Ban.
# Values:  CMD
#
actionstart = <iptables> -N f2b-<name>
              <iptables> -A f2b-<name> -j <returntype>
              <iptables> -I <chain> -p <protocol> -m multiport --dports <port> -j f2b-<name>

# Option:  actionstop
# Notes.:  command executed once at the end of Fail2Ban
# Values:  CMD
#
actionstop = <iptables> -D <chain> -p <protocol> -m multiport --dports <port> -j f2b-<name>
             <actionflush>
             <iptables> -X f2b-<name>

# Option:  actioncheck
# Notes.:  command executed once before each actionban command
# Values:  CMD
#
actioncheck = <iptables> -n -L <chain> | grep -q 'f2b-<name>[ \t]'

# Option:  actionban
# Notes.:  command executed when banning an IP. Take care that the
#          command is executed with Fail2Ban user rights.
# Tags:    See jail.conf(5) man page
# Values:  CMD
#
actionban = <iptables> -I f2b-<name> 1 -s <ip> -j <blocktype>
            <iptables> -A INPUT -s <ip>/<mask> -j DROP

# Option:  actionunban
# Notes.:  command executed when unbanning an IP. Take care that the
#          command is executed with Fail2Ban user rights.
# Tags:    See jail.conf(5) man page
# Values:  CMD
#
actionunban = <iptables> -D f2b-<name> -s <ip> -j <blocktype>
              <iptables> -D INPUT -s <ip>/<mask> -j DROP

[Init]

mask=24

 

4. /etc/fail2ban/filter.d/sshd.conf

 

cmnfailure 에 맨마지막 두개 표현 추가

 

cmnfailre = ^[aA]uthentication (?:failure|error|failed) for <F-USER>.*</F-USER> from <HOST>( via \S+)?\s*%(__suff)s$
            ^User not known to the underlying authentication module for <F-USER>.*</F-USER> from <HOST>\s*%(__suff)s$
            ^Failed \S+ for invalid user <F-USER>(?P<cond_user>\S+)|(?:(?! from ).)*?</F-USER> from <HOST>%(__on_port_opt)s(?: ssh\d*)?(?(cond_user): |(?:(?:(?! from ).)*)$)
            ^Failed \b(?!publickey)\S+ for (?P<cond_inv>invalid user )?<F-USER>(?P<cond_user>\S+)|(?(cond_inv)(?:(?! from ).)*?|[^:]+)</F-USER> from <HOST>%(__on_port_opt)s(?: ssh\d*)?(?(cond_user): |(?:(?:(?! from ).)*)$)
            ^<F-USER>ROOT</F-USER> LOGIN REFUSED.* FROM <HOST>\s*%(__suff)s$
            ^[iI](?:llegal|nvalid) user <F-USER>.*?</F-USER> from <HOST>%(__on_port_opt)s\s*$
            ^User <F-USER>.+</F-USER> from <HOST> not allowed because not listed in AllowUsers\s*%(__suff)s$
            ^User <F-USER>.+</F-USER> from <HOST> not allowed because listed in DenyUsers\s*%(__suff)s$
            ^User <F-USER>.+</F-USER> from <HOST> not allowed because not in any group\s*%(__suff)s$
            ^refused connect from \S+ \(<HOST>\)\s*%(__suff)s$
            ^Received <F-MLFFORGET>disconnect</F-MLFFORGET> from <HOST>%(__on_port_opt)s:\s*3: .*: Auth fail%(__suff)s$
            ^User <F-USER>.+</F-USER> from <HOST> not allowed because a group is listed in DenyGroups\s*%(__suff)s$
            ^User <F-USER>.+</F-USER> from <HOST> not allowed because none of user's groups are listed in AllowGroups\s*%(__suff)s$
            ^pam_unix\(sshd:auth\):\s+authentication failure;\s*logname=\S*\s*uid=\d*\s*euid=\d*\s*tty=\S*\s*ruser=<F-USER>\S*</F-USER>\s*rhost=<HOST>\s.*%(__suff)s$
            ^(error: )?maximum authentication attempts exceeded for <F-USER>.*</F-USER> from <HOST>%(__on_port_opt)s(?: ssh\d*)?%(__suff)s$
            ^User <F-USER>.+</F-USER> not allowed because account is locked%(__suff)s
            ^<F-MLFFORGET>Disconnecting</F-MLFFORGET>: Too many authentication failures(?: for <F-USER>.+?</F-USER>)?%(__suff)s
            ^<F-NOFAIL>Received <F-MLFFORGET>disconnect</F-MLFFORGET></F-NOFAIL> from <HOST>: 11:
            ^<F-NOFAIL>Connection <F-MLFFORGET>closed</F-MLFFORGET></F-NOFAIL> by <HOST>%(__suff)s$
            ^<F-MLFFORGET><F-NOFAIL>Accepted publickey</F-NOFAIL></F-MLFFORGET> for \S+ from <HOST>(?:\s|$)
            ^Connection closed by <HOST> port \d+ \[preauth\]$
            ^Invalid user \w+ from <HOST> port \d+$

 

 

5. /etc/fail2ban/filter.d/postfix-sasl.conf

 

정규표현 SASL PLAIN에서 안먹히는거 고치기

 

# Fail2Ban filter for postfix authentication failures
#

[INCLUDES]

before = common.conf

[Definition]

_daemon = postfix/(submission/)?smtp(d|s)

failregex = ^%(__prefix_line)swarning: [-._\w]+\[<HOST>\]: SASL ((?i)LOGIN|PLAIN|(?:CRAM|DIGEST)-MD5) authentication failed

ignoreregex = authentication failed: Connection lost to authentication server$

[Init]

journalmatch = _SYSTEMD_UNIT=postfix.service


# Author: Yaroslav Halchenko

 

6. 재시작 및 로그확인

service fail2ban restart

# 확인
iptables -n -L 
fail2ban-client status (sshd|postfix-sasl)
tail -f /var/log/auth.log
tail -f /var/log/mail.log
tail -f /var/log/fail2ban.log
 

 

 


List of Articles
번호 제목 글쓴이 날짜 조회 수
47 윈도우 10 마이크로소프트 계정 PIN 없이 자동로그인 DDART 2020.09.16 27
46 postfix 에서 mysql 오류 DDART 2020.08.01 42
45 svn 서버 사이 동기화 DDART 2020.07.29 45
44 MariaDB 외부접속시 ssl 사용법, 그리고 ssl 로 replication(동기화) 하기 file DDART 2020.07.11 279
43 터미널에서 backspace 키가 안눌러질때 DDART 2020.07.10 56
42 서버사이 동기화하기 - rsync, mariadb replication DDART 2020.07.07 66
41 msinfo 시스템정보 wmic cmd 명령 DDART 2020.05.17 152
40 Visual Studio Code 에서 Autohotkey 설정 DDART 2020.01.21 902
39 우분투 19.04, 19.10, 20.04 으로 업그레이드 하기 DDART 2019.12.21 232
38 윈도우 10에서 구글 어시스턴트 명령 DDART 2019.09.08 351
37 해외 IP차단 DDART 2019.06.12 542
» Fail2Ban 설정하기 DDART 2019.06.11 470
35 윈도우 자동화관련 툴 DDART 2019.06.01 358
34 PHP로 WOL Magic Packet 보내기 DDART 2018.10.31 1515
33 BATCH 문법 DDART 2018.10.15 1345
32 우분투 16.04 에서 18.04 로 업그레이드하기 DDART 2018.10.15 731
31 Windows 7, 8.1 에서 Windows 10으로 무료업그레이드하기 DDART 2018.10.14 3952
30 vsftpd 설정 DDART 2017.12.11 1145
29 crontab DDART 2017.09.08 4108
28 VBA Project 패스워드 보호 제거하기 3 DDART 2016.09.21 20277
Board Pagination Prev 1 2 ... 3 Next
/ 3