Vulnerability Discussion
Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks.
Password complexity is one factor of several that determines how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that need to be tested before the password is compromised.
Check
Note: The value to require a number of upper-case characters to be set is expressed as a negative number in "/etc/security/pwquality.conf".
Check the value for "ucredit" in "/etc/security/pwquality.conf" with the following command:
# grep ucredit /etc/security/pwquality.conf
ucredit = -1
If the value of "ucredit" is not set to a negative value, this is a finding.
Fix
Configure the operating system to enforce password complexity by requiring that at least one upper-case character be used by setting the "ucredit" option.
Add the following line to "/etc/security/pwquality.conf" (or modify the line to have the required value):
ucredit = -1