Vulnerability Discussion
The "/etc/shadow-" file is a backup file of "/etc/shadow", and as such, contains the list of local system accounts and password hashes. Protection of this file is critical for system security.
Check
Verify the ownership of the "/etc/shadow-" file with the following command:
$ sudo stat -c "%U %n" /etc/shadow-
root /etc/shadow-
If "/etc/shadow-" file does not have an owner of "root", this is a finding.
Fix
Change the owner of the file /etc/shadow- to root by running the following command:
$ sudo chown root /etc/shadow-