The system must disable accounts after three consecutive unsuccessful logon attempts.

From Red Hat Enterprise Linux 6 Security Technical Implementation Guide

Associated with: CCI-000044

SV-50374r4_rule The system must disable accounts after three consecutive unsuccessful logon attempts.

Vulnerability discussion

Locking out user accounts after a number of incorrect attempts prevents direct password guessing attacks.

Check content

To ensure the failed password attempt policy is configured correctly, run the following command: # grep pam_faillock /etc/pam.d/system-auth /etc/pam.d/password-auth The output should show "deny=3" for both files. If that is not the case, this is a finding.

Fix text

To configure the system to lock out accounts after a number of incorrect logon attempts using "pam_faillock.so", modify the content of both "/etc/pam.d/system-auth" and "/etc/pam.d/password-auth" as follows: Add the following line immediately before the "pam_unix.so" statement in the "AUTH" section: auth required pam_faillock.so preauth silent deny=3 unlock_time=604800 fail_interval=900 Add the following line immediately after the "pam_unix.so" statement in the "AUTH" section: auth [default=die] pam_faillock.so authfail deny=3 unlock_time=604800 fail_interval=900 Add the following line immediately before the "pam_unix.so" statement in the "ACCOUNT" section: account required pam_faillock.so Note that any updates made to "/etc/pam.d/system-auth" and "/etc/pam.d/password-auth" may be overwritten by the "authconfig" program. The "authconfig" program should not be used.

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