4.5.1.6 Ensure the number of changed characters in a new password is configured

Information

The pwquality difok option sets the number of characters in a password that must not be present in the old password.

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.

Solution

Edit or add the following line in /etc/security/pwquality.conf to a value of 2 or more:

difok = 2

See Also

https://workbench.cisecurity.org/benchmarks/13007

Item Details

Category: IDENTIFICATION AND AUTHENTICATION

References: 800-53|IA-5(1), CSCv7|4.4

Plugin: Unix

Control ID: 6e5ffbf50d1a992ddfdea0449499e2cb0b3a7b2e187c098bedd3edc337e87b71