fail2ban/config/filter.d/mongodb-auth.conf

# Fail2Ban filter for unsuccesfull MongoDB authentication attempts
#
# Logfile /var/log/mongodb/mongodb.log
#
# add setting in /etc/mongodb.conf
# logpath=/var/log/mongodb/mongodb.log
#
# and use of the authentication
# auth = true
#

[Definition]
#failregex = ^\s+\[initandlisten\] connection accepted from <HOST>:\d+ \#(?P<__connid>\d+) \(1 connection now open\)<SKIPLINES>\s+\[conn(?P=__connid)\] Failed to authenticate\s+
failregex = ^\s+\[conn(?P<__connid>\d+)\] Failed to authenticate [^\n]+<SKIPLINES>\s+\[conn(?P=__connid)\] end connection <HOST>

ignoreregex =


[Init]
maxlines = 10

# DEV Notes:
#
# Regarding the multiline regex:
#
# There can be a nunber of non-related lines between the first and second part
# of this regex maxlines of 10 is quite generious.
#
# Note the capture __connid, includes the connection ID, used in second part of regex.
#
# The first regex is commented out (but will match also), because it is better to use
# the host from "end connection" line (uncommented above):
#  -  it has the same prefix, searching begins directly with failure message
#     (so faster, because ignores success connections at all)
#  -  it is not so vulnerable in case of possible race condition
#
# Log example:
# 2016-10-20T09:54:27.108+0200 [initandlisten] connection accepted from 127.0.0.1:53276 #1 (1 connection now open)
# 2016-10-20T09:54:27.109+0200 [conn1]  authenticate db: test { authenticate: 1, nonce: "xxx", user: "root", key: "xxx" }
# 2016-10-20T09:54:27.110+0200 [conn1] Failed to authenticate root@test with mechanism MONGODB-CR: AuthenticationFailed UserNotFound Could not find user root@test
# 2016-11-09T09:54:27.894+0100 [conn1] end connection 127.0.0.1:53276 (0 connections now open)
# 2016-11-09T11:55:58.890+0100 [initandlisten] connection accepted from 127.0.0.1:54266 #1510 (1 connection now open)
# 2016-11-09T11:55:58.892+0100 [conn1510]  authenticate db: admin { authenticate: 1, nonce: "xxx", user: "root", key: "xxx" }
# 2016-11-09T11:55:58.892+0100 [conn1510] Failed to authenticate root@admin with mechanism MONGODB-CR: AuthenticationFailed key mismatch
# 2016-11-09T11:55:58.894+0100 [conn1510] end connection 127.0.0.1:54266 (0 connections now open)
#
# Authors: Alexander Finkhäuser
#          Sergey G. Brester (sebres)