This rule confuses the use of 3 and 5 for the number of failures allowed in 15 minutes.
Should be one or the other. Should be 3 (the default).
Rule Title: TOSS must enforce the limit of five consecutive invalid logon attempts by a user during a 15-minute time period.
Discussion: By limiting the number of failed logon attempts, the risk of unauthorized system access via user password guessing, otherwise known as brute-force attacks, is reduced. Limits are imposed by locking the account.
Check Text: Verify the "/etc/security/faillock.conf" file is configured to lock an account after three unsuccessful logon attempts within 15 minutes:
$ sudo grep -e "deny =" -e "fail_interval =" /etc/security/faillock.conf
deny = 3
fail_interval = 900
If the "deny" option is set to "0", more than "3", is missing, or is commented out, this is a finding.
If the "fail_interval" option is set to less than "900", is missing, or is commented out, this is a finding.
Note: If the System Administrator demonstrates the use of an approved centralized account management method that locks an account after three unsuccessful logon attempts within a period of 15 minutes, this requirement is Not Applicable.
Fix Text: Configure the operating system to lock an account when three unsuccessful logon attempts occur in 15 minutes.
Add/Modify the "/etc/security/faillock.conf" file to match the following lines:
deny = 3
fail_interval = 900
References
CCI: CCI-000044: The information system enforces the organization-defined limit of consecutive invalid logon attempts by a user during the organization-defined time period.
NIST SP 800-53 :: AC-7 a
NIST SP 800-53A :: AC-7.1 (ii)
NIST SP 800-53 Revision 4 :: AC-7 a
cdefrates
commented
3 weeks ago
This rule confuses the use of 3 and 5 for the number of failures allowed in 15 minutes.
Should be one or the other. Should be
3(the default).