Vulnerability Discussion
Passwords need to be protected at all times, and encryption is the standard method for protecting passwords. If passwords are not encrypted, they can be plainly read (i.e., clear text) and easily compromised.
Check
Verify that the shadow password suite configuration is set to encrypt passwords with a FIPS 140-2 approved cryptographic hashing algorithm.
Check the hashing algorithm that is being used to hash passwords with the following command:
$ cat /etc/login.defs | grep -i encrypt_method
ENCRYPT_METHOD SHA512
If "ENCRYPT_METHOD" does not equal SHA512 or greater, this is a finding.
Fix
Configure the Ubuntu operating system to encrypt all stored passwords.
Edit/modify the following line in the "/etc/login.defs" file and set "ENCRYPT_METHOD" to SHA512:
ENCRYPT_METHOD SHA512