Arp Spoofing in Feathersjs with Dynamodb

Arp spoofing is a network-layer attack where an attacker sends falsified Address Resolution Protocol (ARP) messages to associate their MAC address with the IP of a legitimate host, typically the gateway or another service in the network path. In a Feathersjs application that uses Amazon DynamoDB as its primary data store, the risk arises not from DynamoDB itself but from how the service is accessed and authenticated within the network topology.

Feathersjs applications often run as Node.js services in containerized or cloud environments, communicating with DynamoDB over HTTPS via the AWS SDK. If an attacker conducts ARP spoofing on the local network segment (for example, within a shared VPC, container network, or development environment), they can intercept or modify traffic between the Feathersjs service and DynamoDB. While DynamoDB enforces strong authentication and encryption in transit, an ARP spoofing attack may enable session hijacking or facilitate additional man-in-the-middle techniques that expose API keys, IAM credentials, or unencrypted internal metadata requests if the application improperly handles AWS credential resolution.

The exposure is specific to the integration pattern: Feathersjs services using the default AWS SDK credential provider chain may inadvertently rely on instance metadata or environment variables that become reachable via a compromised network position during ARP spoofing. For example, if the service uses local environment variables for AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY, an attacker who successfully spoofs the MAC address of the gateway can redirect traffic and potentially capture these credentials if the application logs or error messages leak them. Additionally, if the Feathersjs app communicates with a local proxy or uses IMDSv1 for DynamoDB credential requests, ARP spoofing increases the feasibility of credential interception.

Importantly, DynamoDB’s server-side encryption and IAM policies remain intact; the vulnerability is in the network path and credential exposure surface introduced by the Feathersjs deployment environment. The attack does not alter data in DynamoDB directly but can undermine the confidentiality of the communication channel and the integrity of the authentication process when network isolation is insufficient.

To contextualize the risk, middleBrick scans this attack surface by testing unauthenticated endpoints and evaluating configuration patterns, including how the Feathersjs service integrates with external data stores like DynamoDB, and flags insecure credential handling or missing network hardening as actionable findings.