220-1202 Practice Question: A malicious script is suspected to have changed…

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✓

  chmod 644 /etc/passwd

  Why this is correct

  This command correctly sets the permissions for /etc/passwd. The `6` grants read and write access to the owner (typically root), while the first `4` grants read-only access to the group, and the second `4` grants read-only access to others. This configuration is the secure default, allowing system processes and users to read necessary account information without permitting unauthorized modifications, which is crucial for system functionality and security.

• ✗

  chmod 600 /etc/passwd

  Why it's wrong here

  Applying `chmod 600` to /etc/passwd restricts all access to the file except for the owner, granting only read and write permissions to `root`. While this might seem highly secure, it critically prevents other users and many essential system utilities from reading the file. This would cause critical system functions, such as user authentication and displaying user information, to fail, leading to significant operational issues and system instability.

• ✗

  chmod 755 /etc/passwd

  Why it's wrong here

  Setting /etc/passwd permissions to `755` is inappropriate and introduces a severe security risk. The `7` grants read, write, and execute permissions to the owner, while the `5` grants read and execute permissions to the group and others. Granting execute permissions on a plain text data file like /etc/passwd is entirely unnecessary and could potentially be exploited by malicious scripts attempting to execute non-executable content, compromising system integrity.

• ✗

  chmod 444 /etc/passwd

  Why it's wrong here

  Using `chmod 444` on /etc/passwd makes the file read-only for everyone, including the owner, group, and others. While it allows all users to read the file, it critically removes the owner's (root's) write permission. This prevents any modifications to the user database, meaning operations like adding new users, changing passwords, or updating user information would fail, rendering user management impossible and breaking core system functionality.

Go deeper

Related to this question