UBTU-18-010033 - 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.

Information

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.
Satisfies: SRG-OS-000329-GPOS-00128

Solution

Configure the Ubuntu operating system to utilize 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

See Also

https://dl.dod.cyber.mil/wp-content/uploads/stigs/zip/U_CAN_Ubuntu_18-04_LTS_V2R15_STIG.zip

Item Details

Category: ACCESS CONTROL

References: 800-53|AC-7a., 800-53|AC-7b., CAT|II, CCI|CCI-000044, CCI|CCI-002238, Rule-ID|SV-219166r958388_rule, STIG-ID|UBTU-18-010033, STIG-Legacy|SV-109663, STIG-Legacy|V-100559, Vuln-ID|V-219166

Plugin: Unix

Control ID: 4ecf0c558a73bd764e2ae9b1033c425e44d3410e0fe38a530579717f1bea774d