Information
unlock_time=<n> - The access will be re-enabled after
seconds after the lock out. The value 0 has the same meaning as value never - the access will not be re-enabled without resetting the faillock entries by the faillock(8) command.
Note:
- The default directory that pam_faillock uses is usually cleared on system boot so the access will be also re-enabled after system reboot. If that is undesirable a different tally directory must be set with the dir option.
- It is usually undesirable to permanently lock out users as they can become easily a target of denial of service attack unless the usernames are random and kept secret to potential attackers.
- The maximum configurable value for unlock_time is 604800
Locking out user IDs after
n
unsuccessful consecutive login attempts mitigates brute force password attacks against your systems.
Solution
Set password unlock time to conform to site policy. unlock_time should be 0 (never), or 900 seconds or greater.
Edit /etc/security/faillock.conf and update or add the following line:
unlock_time = 900
Run the following command: remove the unlock_time argument from the pam_faillock.so module in the PAM files:
# grep -Pl -- 'bpam_faillock.soh+([^#
r]+h+)?unlock_timeb' /usr/share/pam-configs/*
Edit any returned files and remove the unlock_time=<N> argument from the pam_faillock.so line(s):
Impact:
Use of unlock_time=0 may allow an attacker to cause denial of service to legitimate users. This will also require a systems administrator with elevated privileges to unlock the account.