Apache-2.2

fail2ban 無法在全新安裝的 ubuntu 14.04 上執行，為什麼？

  • June 24, 2015

安裝和配置fail2ban後，我嘗試使用錯誤密碼通過ssh登錄我的伺服器。經過幾次嘗試，我嘗試使用正確的密碼成功。所以，fail2ban 並沒有禁止允許他登錄的使用者 ip。不管我設置了什麼規則，maxretry = 1 等等。

我的 iptables -L 輸出：

Chain INPUT (policy ACCEPT)
target     prot opt source               destination         
fail2ban-SSH  tcp  --  anywhere             anywhere             tcp dpt:ssh

Chain FORWARD (policy ACCEPT)
target     prot opt source               destination         

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination         

Chain fail2ban-SSH (1 references)
target     prot opt source               destination         
RETURN     all  --  anywhere             anywhere

這是調試日誌，不完整版本如下：

root@host:~# fail2ban-client -v -v -v start
DEBUG  Reading configs for /etc/fail2ban/fail2ban under /etc/fail2ban 
DEBUG  Reading config files: /etc/fail2ban/fail2ban.conf
DEBUG  Reading files: ['/etc/fail2ban/fail2ban.conf']
INFO   Using socket file /var/run/fail2ban/fail2ban.sock
DEBUG  Reading configs for /etc/fail2ban/fail2ban under /etc/fail2ban 
DEBUG  Reading config files: /etc/fail2ban/fail2ban.conf
DEBUG  Reading files: ['/etc/fail2ban/fail2ban.conf']
DEBUG  Reading configs for /etc/fail2ban/jail under /etc/fail2ban 
DEBUG  Reading config files: /etc/fail2ban/jail.conf, /etc/fail2ban/jail.local
DEBUG  Reading files: ['/etc/fail2ban/jail.conf', '/etc/fail2ban/jail.local']
DEBUG  Reading configs for /etc/fail2ban/jail under /etc/fail2ban 
DEBUG  Reading config files: /etc/fail2ban/jail.conf, /etc/fail2ban/jail.local
DEBUG  Reading files: ['/etc/fail2ban/jail.conf', '/etc/fail2ban/jail.local']
DEBUG  Reading configs for /etc/fail2ban/filter.d/sshd under /etc/fail2ban 
DEBUG  Reading config files: /etc/fail2ban/filter.d/sshd.conf
DEBUG  Reading files: ['/etc/fail2ban/filter.d/common.conf', '/etc/fail2ban/filter.d/common.local', '/etc/fail2ban/filter.d/sshd.conf']
DEBUG  Reading configs for /etc/fail2ban/action.d/iptables under /etc/fail2ban 
DEBUG  Reading config files: /etc/fail2ban/action.d/iptables.conf
DEBUG  Reading files: ['/etc/fail2ban/action.d/iptables-blocktype.conf', '/etc/fail2ban/action.d/iptables-blocktype.local', '/etc/fail2ban/action.d/iptables.conf']
DEBUG  Reading configs for /etc/fail2ban/jail under /etc/fail2ban 
DEBUG  Reading config files: /etc/fail2ban/jail.conf, /etc/fail2ban/jail.local
DEBUG  Reading files: ['/etc/fail2ban/jail.conf', '/etc/fail2ban/jail.local']
DEBUG  Reading configs for /etc/fail2ban/jail under /etc/fail2ban 
DEBUG  Reading config files: /etc/fail2ban/jail.conf, /etc/fail2ban/jail.local
DEBUG  Reading files: ['/etc/fail2ban/jail.conf', '/etc/fail2ban/jail.local']
DEBUG  Reading configs for /etc/fail2ban/jail under /etc/fail2ban 
DEBUG  Reading config files: /etc/fail2ban/jail.conf, /etc/fail2ban/jail.local
DEBUG  Reading files: ['/etc/fail2ban/jail.conf', '/etc/fail2ban/jail.local']
DEBUG  Reading configs for /etc/fail2ban/jail under /etc/fail2ban 
DEBUG  Reading config files: /etc/fail2ban/jail.conf, /etc/fail2ban/jail.local
DEBUG  Reading files: ['/etc/fail2ban/jail.conf', '/etc/fail2ban/jail.local']
DEBUG  Reading configs for /etc/fail2ban/jail under /etc/fail2ban 
DEBUG  Reading config files: /etc/fail2ban/jail.conf, /etc/fail2ban/jail.local

[...] SKIPPED SOME READING CONFIG FILES here

DEBUG  Reading files: ['/etc/fail2ban/jail.conf', '/etc/fail2ban/jail.local']
DEBUG  Reading configs for /etc/fail2ban/jail under /etc/fail2ban 
DEBUG  Reading config files: /etc/fail2ban/jail.conf, /etc/fail2ban/jail.local
DEBUG  Reading files: ['/etc/fail2ban/jail.conf', '/etc/fail2ban/jail.local']
INFO   [#         ] Waiting on the server...DEBUG  Starting '/usr/bin/fail2ban-server' with args ['fail2ban-server', '-b', '-s', '/var/run/fail2ban/fail2ban.sock', '-p', '/var/run/fail2ban/fail2ban.pid']
2014-05-22 15:29:14,376 fail2ban.server : INFO   Starting Fail2ban v0.8.11
2014-05-22 15:29:14,376 fail2ban.server : INFO   Starting in daemon mode
DEBUG  OK : 'pong'

DEBUG  OK : 3
DEBUG  OK : '/var/log/fail2ban.log'
DEBUG  OK : 'ssh'
DEBUG  OK : 'warn'
DEBUG  OK : ['/var/log/auth.log']
DEBUG  OK : 1
DEBUG  OK : ['127.0.0.1/8']
DEBUG  OK : 600
DEBUG  OK : 600
DEBUG  OK : ['^\\s*(<[^.]+\\.[^.]+>)?\\s*(?:\\S+ )?(?:kernel: \\[\\d+\\.\\d+\\] )?(?:@vserver_\\S+ )?(?:(?:\\[\\d+\\])?:\\s+[\\[\\(]?sshd(?:\\(\\S+\\))?[\\]\\)]?:?|[\\[\\(]?sshd(?:\\(\\S+\\))?[\\]\\)]?:?(?:\\[\\d+\\])?:?)?\\s(?:\\[ID \\d+ \\S+\\])?\\s*(?:error: PAM: )?[aA]uthentication (?:failure|error) for .* from (?:::f{4,6}:)?(?P<host>[\\w\\-.^_]*\\w)( via \\S+)?\\s*$']
DEBUG  OK : ['^\\s*(<[^.]+\\.[^.]+>)?\\s*(?:\\S+ )?(?:kernel: \\[\\d+\\.\\d+\\] )?(?:@vserver_\\S+ )?(?:(?:\\[\\d+\\])?:\\s+[\\[\\(]?sshd(?:\\(\\S+\\))?[\\]\\)]?:?|[\\[\\(]?sshd(?:\\(\\S+\\))?[\\]\\)]?:?(?:\\[\\d+\\])?:?)?\\s(?:\\[ID \\d+ \\S+\\])?\\s*(?:error: PAM: )?[aA]uthentication (?:failure|error) for .* from (?:::f{4,6}:)?(?P<host>[\\w\\-.^_]*\\w)( via \\S+)?\\s*$', '^\\s*(<[^.]+\\.[^.]+>)?\\s*(?:\\S+ )?(?:kernel: \\[\\d+\\.\\d+\\] )?(?:@vserver_\\S+ )?(?:(?:\\[\\d+\\])?:\\s+[\\[\\(]?sshd(?:\\(\\S+\\))?[\\]\\)]?:?|[\\[\\(]?sshd(?:\\(\\S+\\))?[\\]\\)]?:?(?:\\[\\d+\\])?:?)?\\s(?:\\[ID \\d+ \\S+\\])?\\s*(?:error: PAM: )?User not known to the underlying authentication module for .* from (?:::f{4,6}:)?(?P<host>[\\w\\-.^_]*\\w)\\s*$']

[...] SKIPPED SOME REGEX HERE

DEBUG  OK : 'iptables'
DEBUG  OK : 'iptables -I fail2ban-<name> 1 -s <ip> -j <blocktype>'
DEBUG  OK : 'iptables -D <chain> -p <protocol> --dport <port> -j fail2ban-<name>\niptables -F fail2ban-<name>\niptables -X fail2ban-<name>'
DEBUG  OK : 'iptables -N fail2ban-<name>\niptables -A fail2ban-<name> -j RETURN\niptables -I <chain> -p <protocol> --dport <port> -j fail2ban-<name>'
DEBUG  OK : 'iptables -D fail2ban-<name> -s <ip> -j <blocktype>'
DEBUG  OK : "iptables -n -L <chain> | grep -q 'fail2ban-<name>[ \\t]'"
DEBUG  OK : 'REJECT --reject-with icmp-port-unreachable'
DEBUG  OK : 'tcp'
DEBUG  OK : 'SSH'
DEBUG  OK : 'INPUT'
DEBUG  OK : 'ssh'
DEBUG  OK : None

我的fail2ban.log，jail.local：

tail /var/log/fail2ban.log
2014-05-22 15:30:27,729 fail2ban.server : INFO   Exiting Fail2ban
2014-05-22 15:30:32,668 fail2ban.server : INFO   Changed logging target to /var/log/fail2ban.log for Fail2ban v0.8.11
2014-05-22 15:30:32,668 fail2ban.jail   : INFO   Creating new jail 'ssh'
2014-05-22 15:30:32,668 fail2ban.jail   : INFO   Jail 'ssh' uses poller
2014-05-22 15:30:32,679 fail2ban.jail   : INFO   Initiated 'polling' backend
2014-05-22 15:30:32,680 fail2ban.filter : INFO   Added logfile = /var/log/auth.log
2014-05-22 15:30:32,681 fail2ban.filter : INFO   Set maxRetry = 1
2014-05-22 15:30:32,681 fail2ban.filter : INFO   Set findtime = 600
2014-05-22 15:30:32,682 fail2ban.actions: INFO   Set banTime = 600
2014-05-22 15:30:32,716 fail2ban.jail   : INFO   Jail 'ssh' started

尾 /etc/fail2ban/jail.local

[ssh]
enabled = true
logpath = /var/log/auth.log
filter = sshd
maxretry = 1
action = iptables[name=SSH, port=ssh, protocol=tcp]
port = ssh


tail /var/log/auth.log

tail /var/log/auth.log 是空的！

root@host:~# fail2ban-client -d

['set', 'loglevel', 3]
['set', 'logtarget', '/var/log/fail2ban.log']
['add', 'ssh', 'polling']
['set', 'ssh', 'usedns', 'warn']
['set', 'ssh', 'addlogpath', '/var/log/auth.log']
['set', 'ssh', 'maxretry', 1]
['set', 'ssh', 'addignoreip', '127.0.0.1/8']
['set', 'ssh', 'findtime', 600]
['set', 'ssh', 'bantime', 600]
['set', 'ssh', 'addfailregex', '^\\s*(<[^.]+\\.[^.]+>)?\\s*(?:\\S+ )?(?:kernel: \\[\\d+\\.\\d+\\] )?(?:@vserver_\\S+ )?(?:(?:\\[\\d+\\])?:\\s+[\\[\\(]?sshd(?:\\(\\S+\\))?[\\]\\)]?:?|[\\[\\(]?sshd(?:\\(\\S+\\))?[\\]\\)]?:?(?:\\[\\d+\\])?:?)?\\s(?:\\[ID \\d+ \\S+\\])?\\s*(?:error: PAM: )?[aA]uthentication (?:failure|error) for .* from <HOST>( via \\S+)?\\s*$']
['set', 'ssh', 'addfailregex', '^\\s*(<[^.]+\\.[^.]+>)?\\s*(?:\\S+ )?(?:kernel: \\[\\d+\\.\\d+\\] )?(?:@vserver_\\S+ )?(?:(?:\\[\\d+\\])?:\\s+[\\[\\(]?sshd(?:\\(\\S+\\))?[\\]\\)]?:?|[\\[\\(]?sshd(?:\\(\\S+\\))?[\\]\\)]?:?(?:\\[\\d+\\])?:?)?\\s(?:\\[ID \\d+ \\S+\\])?\\s*(?:error: PAM: )?User not known to the underlying authentication module for .* from <HOST>\\s*$']
['set', 'ssh', 'addfailregex', '^\\s*(<[^.]+\\.[^.]+>)?\\s*(?:\\S+ )?(?:kernel: \\[\\d+\\.\\d+\\] )?(?:@vserver_\\S+ )?(?:(?:\\[\\d+\\])?:\\s+[\\[\\(]?sshd(?:\\(\\S+\\))?[\\]\\)]?:?|[\\[\\(]?sshd(?:\\(\\S+\\))?[\\]\\)]?:?(?:\\[\\d+\\])?:?)?\\s(?:\\[ID \\d+ \\S+\\])?\\s*Failed \\S+ for .*? from <HOST>(?: port \\d*)?(?: ssh\\d*)?(: (ruser .*|(\\S+ ID \\S+ \\(serial \\d+\\) CA )?\\S+ (?:[\\da-f]{2}:){15}[\\da-f]{2}(, client user ".*", client host ".*")?))?\\s*$']
['set', 'ssh', 'addfailregex', '^\\s*(<[^.]+\\.[^.]+>)?\\s*(?:\\S+ )?(?:kernel: \\[\\d+\\.\\d+\\] )?(?:@vserver_\\S+ )?(?:(?:\\[\\d+\\])?:\\s+[\\[\\(]?sshd(?:\\(\\S+\\))?[\\]\\)]?:?|[\\[\\(]?sshd(?:\\(\\S+\\))?[\\]\\)]?:?(?:\\[\\d+\\])?:?)?\\s(?:\\[ID \\d+ \\S+\\])?\\s*ROOT LOGIN REFUSED.* FROM <HOST>\\s*$']
['set', 'ssh', 'addfailregex', '^\\s*(<[^.]+\\.[^.]+>)?\\s*(?:\\S+ )?(?:kernel: \\[\\d+\\.\\d+\\] )?(?:@vserver_\\S+ )?(?:(?:\\[\\d+\\])?:\\s+[\\[\\(]?sshd(?:\\(\\S+\\))?[\\]\\)]?:?|[\\[\\(]?sshd(?:\\(\\S+\\))?[\\]\\)]?:?(?:\\[\\d+\\])?:?)?\\s(?:\\[ID \\d+ \\S+\\])?\\s*[iI](?:llegal|nvalid) user .* from <HOST>\\s*$']
['set', 'ssh', 'addfailregex', '^\\s*(<[^.]+\\.[^.]+>)?\\s*(?:\\S+ )?(?:kernel: \\[\\d+\\.\\d+\\] )?(?:@vserver_\\S+ )?(?:(?:\\[\\d+\\])?:\\s+[\\[\\(]?sshd(?:\\(\\S+\\))?[\\]\\)]?:?|[\\[\\(]?sshd(?:\\(\\S+\\))?[\\]\\)]?:?(?:\\[\\d+\\])?:?)?\\s(?:\\[ID \\d+ \\S+\\])?\\s*User .+ from <HOST> not allowed because not listed in AllowUsers\\s*$']
['set', 'ssh', 'addfailregex', '^\\s*(<[^.]+\\.[^.]+>)?\\s*(?:\\S+ )?(?:kernel: \\[\\d+\\.\\d+\\] )?(?:@vserver_\\S+ )?(?:(?:\\[\\d+\\])?:\\s+[\\[\\(]?sshd(?:\\(\\S+\\))?[\\]\\)]?:?|[\\[\\(]?sshd(?:\\(\\S+\\))?[\\]\\)]?:?(?:\\[\\d+\\])?:?)?\\s(?:\\[ID \\d+ \\S+\\])?\\s*User .+ from <HOST> not allowed because listed in DenyUsers\\s*$']
['set', 'ssh', 'addfailregex', '^\\s*(<[^.]+\\.[^.]+>)?\\s*(?:\\S+ )?(?:kernel: \\[\\d+\\.\\d+\\] )?(?:@vserver_\\S+ )?(?:(?:\\[\\d+\\])?:\\s+[\\[\\(]?sshd(?:\\(\\S+\\))?[\\]\\)]?:?|[\\[\\(]?sshd(?:\\(\\S+\\))?[\\]\\)]?:?(?:\\[\\d+\\])?:?)?\\s(?:\\[ID \\d+ \\S+\\])?\\s*User .+ from <HOST> not allowed because not in any group\\s*$']
['set', 'ssh', 'addfailregex', '^\\s*(<[^.]+\\.[^.]+>)?\\s*(?:\\S+ )?(?:kernel: \\[\\d+\\.\\d+\\] )?(?:@vserver_\\S+ )?(?:(?:\\[\\d+\\])?:\\s+[\\[\\(]?sshd(?:\\(\\S+\\))?[\\]\\)]?:?|[\\[\\(]?sshd(?:\\(\\S+\\))?[\\]\\)]?:?(?:\\[\\d+\\])?:?)?\\s(?:\\[ID \\d+ \\S+\\])?\\s*refused connect from \\S+ \\(<HOST>\\)\\s*$']
['set', 'ssh', 'addfailregex', '^\\s*(<[^.]+\\.[^.]+>)?\\s*(?:\\S+ )?(?:kernel: \\[\\d+\\.\\d+\\] )?(?:@vserver_\\S+ )?(?:(?:\\[\\d+\\])?:\\s+[\\[\\(]?sshd(?:\\(\\S+\\))?[\\]\\)]?:?|[\\[\\(]?sshd(?:\\(\\S+\\))?[\\]\\)]?:?(?:\\[\\d+\\])?:?)?\\s(?:\\[ID \\d+ \\S+\\])?\\s*User .+ from <HOST> not allowed because a group is listed in DenyGroups\\s*$']
['set', 'ssh', 'addfailregex', "^\\s*(<[^.]+\\.[^.]+>)?\\s*(?:\\S+ )?(?:kernel: \\[\\d+\\.\\d+\\] )?(?:@vserver_\\S+ )?(?:(?:\\[\\d+\\])?:\\s+[\\[\\(]?sshd(?:\\(\\S+\\))?[\\]\\)]?:?|[\\[\\(]?sshd(?:\\(\\S+\\))?[\\]\\)]?:?(?:\\[\\d+\\])?:?)?\\s(?:\\[ID \\d+ \\S+\\])?\\s*User .+ from <HOST> not allowed because none of user's groups are listed in AllowGroups\\s*$"]
['set', 'ssh', 'addaction', 'iptables']
['set', 'ssh', 'actionban', 'iptables', 'iptables -I fail2ban-<name> 1 -s <ip> -j <blocktype>']
['set', 'ssh', 'actionstop', 'iptables', 'iptables -D <chain> -p <protocol> --dport <port> -j fail2ban-<name>\niptables -F fail2ban-<name>\niptables -X fail2ban-<name>']
['set', 'ssh', 'actionstart', 'iptables', 'iptables -N fail2ban-<name>\niptables -A fail2ban-<name> -j RETURN\niptables -I <chain> -p <protocol> --dport <port> -j fail2ban-<name>']
['set', 'ssh', 'actionunban', 'iptables', 'iptables -D fail2ban-<name> -s <ip> -j <blocktype>']
['set', 'ssh', 'actioncheck', 'iptables', "iptables -n -L <chain> | grep -q 'fail2ban-<name>[ \\t]'"]
['set', 'ssh', 'setcinfo', 'iptables', 'blocktype', 'REJECT --reject-with icmp-port-unreachable']
['set', 'ssh', 'setcinfo', 'iptables', 'protocol', 'tcp']
['set', 'ssh', 'setcinfo', 'iptables', 'name', 'SSH']
['set', 'ssh', 'setcinfo', 'iptables', 'chain', 'INPUT']
['set', 'ssh', 'setcinfo', 'iptables', 'port', 'ssh']
['start', 'ssh']

其他資訊：

dpkg -l |grep fail  
ii  fail2ban                         0.8.11-1                      all          ban hosts that cause multiple authentication errors


/etc/init.d/fail2ban status      
* Status of authentication failure monitor                                                                             *  fail2ban is running

fail2ban-client status   
Status
|- Number of jail:  1
`- Jail list:       ssh

有什麼提示嗎？感謝您的關注！

不確定是否相關，但我刪除並重新創建了/var/log/auth.log，因為我需要清空它以調試情況

這很可能是問題所在。syslog 守護程序可能仍在寫入原始 fd。您應該嘗試重新啟動 syslog 守護程序以查看它是否開始記錄到正確的文件。

service rsyslog restart

一旦您將消息發送到 auth.log，它應該開始工作。

有時這是因為__bsd_syslog_verbose錯誤。fail2ban 期望 /var/log/auth.log 以YYYY.MM.DD（即：2014.10.15）開始但讀取的日誌MMM DD（即：10 月 15 日）

要解決此問題，您需要執行以下操作：

cp /etc/fail2ban/filter.d/common.conf /etc/fail2ban/filter.d/common.local

編輯common.local和設置：

__bsd_syslog_verbose = (<[^.]+ [^.]+>)

重啟fail2ban：

Ubuntu（不要使用重啟）：

sudo service fail2ban stop
sudo service fail2ban start

引用自：https://serverfault.com/questions/597832

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