File Permission Correction.md

Problem Statement

After conducting a security audit within the Stratos DC, the Nautilus security team discovered misconfigured permissions on critical files. To address this, corrective actions are being taken by the production support team. Specifically, the file named /etc/hosts on Nautilus App 1 server requires adjustments to its Access Control Lists (ACLs) as follows:

1. The file's user owner and group owner should be set to root.

2. Others should possess read only permissions on the file.

3. User kirsty must not have any permissions on the file.

4. User jerome should be granted read only permission on the file.

Solution

1. Connect to Nautilus App 1 Server

Log in to the server as the user tony:

ssh tony@stapp01

2. Switch to the Root User

sudo su

3. Check Current ACLs and Permissions

Verify the current ACLs on /etc/hosts:

getfacl /etc/hosts

• Output Example:

  getfacl: Removing leading '/' from absolute path names
  # file: etc/hosts
  # owner: root
  # group: root
  user::rw-
  group::r--
  other::r--
  

4. Ensure the File Ownership is Correct

chown root:root /etc/hosts

5. Create the User kirsty

 id kristy
 
 #  id: ‘kristy’: no such user

useradd kirsty

6. Set ACLs on the File

1. Remove All Permissions for kirsty:

   setfacl -m u:kirsty:0 /etc/hosts

2. Grant Read-Only Permissions to jerome:

   setfacl -m u:jerome:r /etc/hosts

7. Verify the Updated ACLs

getfacl /etc/hosts

• Expected Output:

  getfacl: Removing leading '/' from absolute path names
  # file: etc/hosts
  # owner: root
  # group: root
  user::rw-
  user:jerome:r--
  user:kirsty:---
  group::r--
  mask::r--
  other::r--