Publicly Accessible RDS and Unrestricted Security Groups: The Cost Side of Risky Cloud Config
Security findings and cost findings are usually filed by different teams into different tools, and treated as different kinds of problem. But a specific set of configurations sits squarely in both piles: a database open to the internet, a security group accepting traffic from anywhere, an IAM role with a wildcard where a scope should be. The security report calls them risk. The invoice,…
A database with a PubliclyAccessible setting and a security group that permits traffic from any IP address creates a situation where cloud configurations overlap both risk and cost concerns. Treat this combination as a single category to involve both security and finance teams simultaneously. Publicly accessible RDS instances are not just a risk to security, but also a drain on resources and money.
Internet-facing databases endure constant scans and connection attempts, using up connections, CPU, and may even necessitate upgrading instances that wouldn't be necessary with a private subnet. Every byte of data served outward from an exposed endpoint incurs internet egress charges. To verify the presence of such configurations, run the command `aws rds describe-db-instances --query 'DBInstances[?PubliclyAccessible].DBInstanceIdentifier'`.
The ideal situation is an empty list, with access restricted via VPC peering, private endpoints, or a bastion pattern. Security groups with unrestricted inbound rules (0.0.0.0/0) and unrestricted IAM roles with wildcard permissions (AdministratorAccess or Principal: *) increase the attack surface and can lead to costly consequences.
Companies often detect breaches through unexpected bills, such as a $40,000 spike caused by cryptocurrency mining on unused GPU instances. Wildcard IAM roles, while not directly costing anything while unused, define the potential impact if exploited. Mitigations, such as defining role scopes, requiring MFA, and alerting on broad usage, are inexpensive.
A shared audit list, including both risk and cost implications, can help prioritize items for quicker resolution. Instituting this approach ensures that both security and cost teams address the same issue, leading to more efficient management of cloud resources.
Written by urgent.news from Dev.to's reporting — not their text. Machine-written — may contain errors; check the original before relying on it.
