The Ubuntu operating system must be configured so that three consecutive invalid logon attempts by a user automatically locks the account until released by an administrator

The Ubuntu operating system must be configured so that three consecutive invalid logon attempts by a user automatically locks the account until released by an administrator

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The Ubuntu operating system must be configured so that three consecutive invalid logon attempts by a user automatically locks the account until released by an administrator.

STIG ID: UBTU-18-010033 | SRG: SRG-OS-000021-GPOS-00005 | Severity: medium | CCI: CCI-000044,CCI-002238 | Vulnerability Id: V-219166 Vulnerability Discussion By limiting the number of failed logon attempts, the risk of unauthorised system access via user password guessing, otherwise known as brute-force attacks, is reduced. Limits are imposed by locking the account. Satisfies: SRG-OS-000329-GPOS-00128 Check Verify that the Ubuntu operating system utilizes the “pam_faillock” module with the following command: $ grep faillock /etc/pam.d/common-auth

auth [default=die] pam_faillock.so authfail auth sufficient pam_faillock.so authsucc

If the pam_faillock.so module is not present in the “/etc/pam.d/common-auth” file, this is a finding.

Verify the pam_faillock module is configured to use the following options: $ sudo egrep ‘silent|audit|deny|fail_interval| unlock_time’ /etc/security/faillock.conf

audit silent deny = 3 fail_interval = 900 unlock_time = 0

If the “silent” keyword is missing or commented out, this is a finding. If the “audit” keyword is missing or commented out, this is a finding. If the “deny” keyword is missing, commented out, or set to a value greater than 3, this is a finding. If the “fail_interval” keyword is missing, commented out, or set to a value greater than 900, this is a finding. If the “unlock_time” keyword is missing, commented out, or is not set to 0, this is a finding. Fix Configure the Ubuntu operating system to utilise the “pam_faillock” module.

Edit the /etc/pam.d/common-auth file.

Add the following lines below the “auth” definition for pam_unix.so: auth [default=die] pam_faillock.so authfail auth sufficient pam_faillock.so authsucc

Configure the “pam_faillock” module to use the following options:

Edit the /etc/security/faillock.conf file and add/update the following keywords and values: audit silent deny = 3 fail_interval = 900 unlock_time = 0