CIS Ubuntu 14.04 LTS - 5.3.1 Ensure password creation requirements are configured

5.3.1 Ensure password creation requirements are configured (Scored)

Profile Applicability

• Level 1 - Server
• Level 1 - Workstation

Description

The pam_pwquality.so module checks the strength of passwords. It performs checks such as making sure a password is not a dictionary word, it is a certain length, contains a mix of characters (e.g. alphabet, numeric, other) and more. The following are definitions of the pam_pwquality.so options:

• retry=3 - Allow 3 tries before sending back a failure.

The following options are set in the /etc/security/pwquality.conf file:

• minlen = 14 - password must be 14 characters or more
• dcredit = -1 - provide at least one digit
• ucredit = -1 - provide at least one uppercase character
• ocredit = -1 - provide at least one special character
• lcredit = -1 - provide at least one lowercase character

The settings shown above are one possible policy. Alter these values to conform to your own organization's password policies.

Rationale

Strong passwords protect systems from being hacked through brute force methods.

Audit Procedure

Run the following commands and verify all password requirements conform to organization policy and minlen is 14 or more:

grep pam_pwquality.so /etc/pam.d/common-password
grep ^minlen /etc/security/pwquality.conf
grep ^dcredit /etc/security/pwquality.conf
grep ^lcredit /etc/security/pwquality.conf
grep ^ocredit /etc/security/pwquality.conf
grep ^ucredit /etc/security/pwquality.conf

Expected Result

password requisite pam_pwquality.so retry=3
minlen = 14
dcredit = -1
lcredit = -1
ocredit = -1
ucredit = -1

Remediation

Run the following command to install the pam_pwquality module:

apt-get install libpam-pwquality

Edit the /etc/pam.d/common-password file to include the appropriate options for pam_pwquality.so and to conform to site policy:

password requisite pam_pwquality.so retry=3

Edit /etc/security/pwquality.conf to add or update the following settings to conform to site policy:

minlen = 14
dcredit = -1
ucredit = -1
ocredit = -1
lcredit = -1

Default Value

No password quality requirements configured by default.

References

• CIS Controls: 5.7 - User Accounts Shall Use Long Passwords
• CIS Controls: 16.12 - Use Long Passwords For All User Accounts

Profile

• Level 1 - Server
• Level 1 - Workstation