fail2ban/config/filter.d/vsftpd.conf

# Fail2Ban configuration file
#
# Author: Cyril Jaquier
#
#

[Definition]

# Option: failregex
# 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>[\w\-.^_]+)
# Values: TEXT
#
failregex = vsftpd(?:\(pam_unix\))?(?:\[\d+\])?:.* authentication failure; .* rhost=<HOST>(?:\s+user=\S*)?\s*$
            \[.+\] FAIL LOGIN: Client "<HOST>"\s*$

# Option:  ignoreregex
# Notes.:  regex to ignore. If this regex matches, the line is ignored.
# Values:  TEXT
#
ignoreregex =