Description: 

Security groups provide stateful filtering of ingress/egress network traffic to AWS resources. It is recommended that no security group allows unrestricted ingress access to Oracle ports 1521 or 2483.

If restricted ingress access to Oracle ports means we do not allow to access my database.


Rationale: 

Removing unfettered connectivity to remote console services, and nobody will access my internal database server or Oracle, reduces a database server’s exposure to risk. Ensure no security groups allow ingress from 0.0.0.0/0 or::/0 to Oracle ports 1521 or 2483.


Impact:

If we do not allow unrestricted ingress/inbound access to Oracle ports 1521 or 2483, it can minimize the opportunities for malicious activity such as hacking, data loss, and all multiple types of attacks( brute-force attacks, Denial of Service (DoS) attacks, etc).

For updating an existing environment, care should be taken to ensure that administrators currently relying on an existing ingress from 0.0.0.0/0 have access to Oracle ports 1521 or 2483 through another security group. 


Default Value: 

Inbound

Type

Protocol

Port Range

Source

Description

All traffic

All

All

Security Group ID
(e.g.:- sg-dedc3c97 / default)

For the associated instances, inbound traffic allows network interfaces that are assigned to the same security group.


Audit: 

  1. Sign in to the AWS Management Console.

  2. Go to EC2 dashboard at https://console.aws.amazon.com/ec2/.

  3. Click on Security Groups, under NETWORK & SECURITY section, in the left navigation pane 

  4. Select the Inbound tab 

  5. Verify the value in the Source column for any inbound rules with the Port Range set to 1521 have the source set to 0.0.0.0/0 or ::/0 (Anywhere), then the selected security group allows unrestricted data traffic on port 1521.


Via CLI:

The following command describes a security group the command you can use for each security groups individual to check which IP or ports inbound or outbound:

aws ec2 describe-security-groups --group-ids <secuiryt_group_id>


Remediation:

Pre-Requisite:

  1. Before start, the below implementation steps write all configuration which IP and which port in the inbound.

  2. Avoid the login through the Root user.

  3. Only authorized persons (i.e, admins) can access the Security Groups.

  4. You cannot delete the default security groups but you can edit and modify them but here so you can create security groups and create your own rules in them.

  5. Do not attach the default security group to any EC2 instance if you do not modify any default rules in inbound or outbound.

Implementation Steps:


Step 1: Sign in to the AWS Management Console.

Step 2: Go to EC2 dashboard at https://console.aws.amazon.com/ec2/.

Step 3:  Click on Security Groups, under NETWORK & SECURITY section, in the left navigation pane

Step 4: Select the appropriate security group (see Audit section to identify the right one(s)).

Step 5: Select the Inbound tab and click the Edit inbound rules button.

Step 6: In the Edit inbound rules dialog box, go to source column and perform one of the following actions to restrict the inbound traffic: Click on source dropdown

  1. Select My IP to allow inbound traffic only from your machine (i.e, from your IP address only).

  2. Select Custom and enter IP addresses or name or ID of another security group  based on your access requirements


Step7: Click Save to apply the changes.

 

Backout Plan:

If you want to proceed with previous settings go through the Implementation steps section and set all previous policies that you have written somewhere.

 

Or else you can delete the security group you created

Step 1: Sign in to the AWS Management Console.

Step 2: Go to EC2 dashboard at https://console.aws.amazon.com/ec2/.

Step 3: Click on Security Groups, under NETWORK & SECURITY section, in the left navigation pane

Step 4: Open the security group by clicking on security group ID 

Step 5: Click on Actions dropdown and select Delete Security groups

Via CLI:

The following command is used to delete created security group id in the security_group_id enter the security group id which you show on your console.