The operating system must enforce an account lockout time period of 15 minutes in which three consecutive invalid logon attempts by a user are made.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-67737	AOSX-11-001324	SV-82227r1_rule		Medium

Description
Setting a lockout time period of 15 minutes is an effective deterrent against brute forcing that also makes allowances for legitimate mistakes by users. When three invalid logon attempts are made, the account will be locked.

STIG	Date
Apple OS X 10.11 Security Technical Implementation Guide	2017-07-11

Details

Check Text ( C-68303r1_chk )
Password policy can be set with a configuration profile or the pwpolicy utility. If password policy is set with a configuration profile, run the following command to check if the system has the correct setting for the logon reset timer: /usr/sbin/system_profiler SPConfigurationProfileDataType \| /usr/bin/grep 'minutesUntilFailedLoginReset' If "minutesUntilFailedLoginReset" is not set to "15", this is a finding. If password policy is set with the pwpolicy utility, the variable names may vary depending on how the policy was set. To check if the password policy is configured to disable an account for 15 minutes after 3 unsuccessful logon attempts, run the following command to output the password policy to the screen: /usr/bin/sudo /usr/bin/pwpolicy getaccountpolicies Look for the line "policyCategoryAuthentication". If this does not exist, and password policy is not controlled by a directory server, this is a finding. In the array that follows, there should one or more sections that describe policy checks. One should contain a that allows users to log on if "policyAttributeFailedAuthentications" is less than "policyAttributeMaximumFailedAuthentications". Under policyParameters, "policyAttributeMaximumFailedAuthentications" should be set to "3". If "policyAttributeMaximumFailedAuthentications" is not set to "3", this is a finding. In the same check or in another section, there should be a that allows users to log on if the "policyAttributeCurrentTime" is greater than the result of adding "15" minutes (900 seconds) to "policyAttributeLastFailedAuthenticationTime". The check might use a variable defined in its "policyParameters section". If the check does not exist or if the check adds too great an amount of time, this is a finding.

Check Text ( C-68303r1_chk )

Password policy can be set with a configuration profile or the pwpolicy utility. If password policy is set with a configuration profile, run the following command to check if the system has the correct setting for the logon reset timer:

/usr/sbin/system_profiler SPConfigurationProfileDataType | /usr/bin/grep 'minutesUntilFailedLoginReset'

If "minutesUntilFailedLoginReset" is not set to "15", this is a finding.

If password policy is set with the pwpolicy utility, the variable names may vary depending on how the policy was set. To check if the password policy is configured to disable an account for 15 minutes after 3 unsuccessful logon attempts, run the following command to output the password policy to the screen:

/usr/bin/sudo /usr/bin/pwpolicy getaccountpolicies

Look for the line "policyCategoryAuthentication".

If this does not exist, and password policy is not controlled by a directory server, this is a finding.

In the array that follows, there should one or more sections that describe policy checks. One should contain a that allows users to log on if "policyAttributeFailedAuthentications" is less than "policyAttributeMaximumFailedAuthentications". Under policyParameters, "policyAttributeMaximumFailedAuthentications" should be set to "3".

If "policyAttributeMaximumFailedAuthentications" is not set to "3", this is a finding.

In the same check or in another section, there should be a that allows users to log on if the "policyAttributeCurrentTime" is greater than the result of adding "15" minutes (900 seconds) to "policyAttributeLastFailedAuthenticationTime". The check might use a variable defined in its "policyParameters section".

If the check does not exist or if the check adds too great an amount of time, this is a finding.

Fix Text (F-73851r1_fix)
This setting may be enforced using the "Passcode Policy" configuration profile or by a directory server. The following two lines within the configuration enforce lockout expiration to "15" minutes: autoEnableInSeconds 900 To set the password policy without a configuration profile, run the following command to save a copy of the current "pwpolicy" account policy file: /usr/bin/sudo /usr/bin/pwpolicy getaccountpolicies \| tail -n +2 > pwpolicy.plist Open the generated file in a text editor and ensure it contains the following text after the opening tag and before the closing tag. Replace first with if necessary. policyCategoryAuthentication policyContent (policyAttributeFailedAuthentications < policyAttributeMaximumFailedAuthentications) OR (policyAttributeCurrentTime > (policyAttributeLastFailedAuthenticationTime + autoEnableInSeconds)) policyIdentifier Authentication Lockout policyParameters autoEnableInSeconds 900 policyAttributeMaximumFailedAuthentications 3 If the line "policyCategoryAuthentication" already exists, the following text should be used instead and inserted after the first tag that follows it: policyContent (policyAttributeFailedAuthentications < policyAttributeMaximumFailedAuthentications) OR (policyAttributeCurrentTime > (policyAttributeLastFailedAuthenticationTime + autoEnableInSeconds)) policyIdentifier Authentication Lockout policyParameters autoEnableInSeconds 900 policyAttributeMaximumFailedAuthentications 3 After saving the file and exiting to the command prompt, run the following command to load the new policy file: /usr/bin/sudo /usr/bin/pwpolicy setaccountpolicies pwpolicy.plist Note: Updates to password restrictions must be thoroughly evaluated in a test environment. Mistakes in configuration may block password change and local user creation operations, as well as, lock out all local users, including administrators.

Fix Text (F-73851r1_fix)

This setting may be enforced using the "Passcode Policy" configuration profile or by a directory server.

The following two lines within the configuration enforce lockout expiration to "15" minutes:

autoEnableInSeconds
900

To set the password policy without a configuration profile, run the following command to save a copy of the current "pwpolicy" account policy file:

/usr/bin/sudo /usr/bin/pwpolicy getaccountpolicies | tail -n +2 > pwpolicy.plist

Open the generated file in a text editor and ensure it contains the following text after the opening tag and before the closing tag.

Replace first with if necessary.

policyCategoryAuthentication

policyContent
(policyAttributeFailedAuthentications < policyAttributeMaximumFailedAuthentications) OR (policyAttributeCurrentTime > (policyAttributeLastFailedAuthenticationTime + autoEnableInSeconds))
policyIdentifier
Authentication Lockout
policyParameters

autoEnableInSeconds
900
policyAttributeMaximumFailedAuthentications
3

If the line "policyCategoryAuthentication" already exists, the following text should be used instead and inserted after the first tag that follows it:

policyContent
(policyAttributeFailedAuthentications < policyAttributeMaximumFailedAuthentications) OR (policyAttributeCurrentTime > (policyAttributeLastFailedAuthenticationTime + autoEnableInSeconds))
policyIdentifier
Authentication Lockout
policyParameters

autoEnableInSeconds
900
policyAttributeMaximumFailedAuthentications
3

After saving the file and exiting to the command prompt, run the following command to load the new policy file:

/usr/bin/sudo /usr/bin/pwpolicy setaccountpolicies pwpolicy.plist

Note: Updates to password restrictions must be thoroughly evaluated in a test environment. Mistakes in configuration may block password change and local user creation operations, as well as, lock out all local users, including administrators.