UBTU-20-010072 - The Ubuntu operating system must automatically lock an account until the locked account is released by an administrator when three unsuccessful logon attempts have been made.

Information

By limiting the number of failed logon attempts, the risk of unauthorized system access via user password guessing, otherwise known as brute-forcing, is reduced. Limits are imposed by locking the account.

Satisfies: SRG-OS-000329-GPOS-00128, SRG-OS-000021-GPOS-00005

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_20-04_LTS_V1R10_STIG.zip

Item Details

Category: ACCESS CONTROL

References: 800-53|AC-7a., 800-53|AC-7b., CAT|III, CCI|CCI-000044, CCI|CCI-002238, Rule-ID|SV-238235r853414_rule, STIG-ID|UBTU-20-010072, Vuln-ID|V-238235

Plugin: Unix

Control ID: c74bf6f60ec115f81a790f806adf5453023f28133b3fd721b9976a71b1b7cf85