Vulnerability Discussion
If the Ubuntu operating system allows the user to select passwords based on dictionary words, then this increases the chances of password compromise by increasing the opportunity for successful guesses and brute-force attacks.
Check
Verify that the Ubuntu operating system uses the cracklib library to prevent the use of dictionary words with the following command:
# grep dictcheck /etc/security/pwquality.conf
dictcheck=1
If the "dictcheck" parameter is not set to "1", or is commented out, this is a finding.
Fix
Configure the Ubuntu operating system to prevent the use of dictionary words for passwords.
Add or update the following line in the "/etc/security/pwquality.conf" file to include the "dictcheck=1" parameter:
dictcheck=1