AWS Elastic Load Balancer: Insecure ELB Security Policy


AWS Elastic Load Balancing (ELB) allows users to define security policies which determine the SSL/TLS protocols and ciphers the load balancer uses when negotiating connections between the client and the load balancer. An insecure security policy could expose the traffic to vulnerabilities such as weak ciphers or outdated protocols, leading to potential man-in-the-middle attacks, data breaches, and other security threats.


1. Update the ELB Security Policy:

A recommended approach is to use the most recent predefined security policy that AWS provides, which is designed to give a balance between security and compatibility.

AWS Management Console:
  • Navigate to the Elastic Load Balancing service.
  • Select your Load Balancer from the list.
  • In the Listeners tab, choose the HTTPS/TLS listener you want to modify.
  • Update the SSL policy to the latest predefined security policy (e.g., ELBSecurityPolicy-TLS-1-2-Ext-2018-06 or later).
aws elbv2 modify-listener \
    --listener-arn "arn:aws:elasticloadbalancing:region:account-id:listener/app/load-balancer-name/load-balancer-id" \
    --ssl-policy ELBSecurityPolicy-TLS-1-2-Ext-2018-06
resource "aws_lb_listener" "example" {
  load_balancer_arn = aws_lb.example.arn
  port              = 443
  protocol          = "HTTPS"
  ssl_policy        = "ELBSecurityPolicy-TLS-1-2-Ext-2018-06"

  certificate {
    certificate_arn = aws_acm_certificate.example.arn

  default_action {
    type = "forward"
    target_group_arn = aws_lb_target_group.example.arn

2. Regularly Monitor for Deprecated Ciphers and Protocols:

  • Regularly check for updates to AWS predefined security policies and ensure your ELB configurations are using the most recent and secure versions.
  • Use AWS Trusted Advisor to identify ELBs with potentially insecure configurations and apply recommended fixes.

3. Policy and Training:

  • Ensure all team members are informed about the importance of secure ELB security policies. Regularly review and update policies, and conduct training sessions to ensure best practices are followed.

Utilizing a secure ELB security policy is crucial to ensure the safety and security of the traffic between clients and the Elastic Load Balancer. By regularly updating and monitoring the security policy, organizations can help prevent potential security threats and ensure robust data protection.