What is a shadow password file?
A shadow password file, also known as /etc/shadow, is a system file in Linux that stores encrypted user passwords and is accessible only to the root user, preventing unauthorized users or malicious actors from breaking into the system.
The common practice of storing passwords in the /etc/passwd file leaves the Linux system vulnerable to break-in attempts. To eliminate this vulnerability, newer Linux systems use the /etc/shadow file to store user passwords instead.
Traditional password files are maintained in /etc/passwd, but the actual hashed passwords are stored in /etc/shadow.