Network misconfigurations

Elastic Load Balancer (ELB) allows ingress access to DNS port 53

Risk Level

Hazardous (3)

Platform(s)
Compliance Frameworks

Description

DNS port - 53 is used to query Domain Names to IP address. Allowing inbound traffic from all external IP addresses to DNS port can be vulnerable to DNS Hijacking, Cache Poisoning, and DNS Tunnelling attack. It is a best practice to restrict access from known public DNS server to destination port 53.
  • Recommended Mitigation

    It is recommended to replace the source IP of the rule with a specific IP address or delete the rule.