Microservices Security Testing Services

The core problem with microservices security is that internal calls are treated as trusted because they come from inside the cluster. An attacker who compromises a low-value service, or finds an SSRF that can reach internal hostnames, inherits that trust. Suddenly a payments service or an admin API is answering requests it assumed could only come from a sibling. We test that assumption directly by trying to speak to internal services from where an attacker would actually stand.

In a well-run system every service validates the same token the same way. In practice they drift. One service checks the signature and the audience, another only checks the signature, a third trusts a header the gateway was supposed to strip. A token minted for a narrow purpose then works far beyond its intended scope. Finding these inconsistencies means comparing how each service reads the same credential, which is manual, careful work.

You cannot secure services you cannot see. We build a picture of the services, how they call each other, where the gateway sits, which endpoints are meant to be internal, and how identity flows between them. This map drives everything that follows and often surfaces surprises on its own, such as an internal admin service exposed at the edge.

We start where an attacker starts, at the public gateway. We test its routing rules for paths that reach services they should not, header-trust issues where a spoofed header grants internal privilege, and authorization gaps where the gateway authenticates a caller but forwards it to a service that authorizes nothing further.

This is the heart of the engagement. From a foothold, whether a low-privilege account, a compromised service, or an SSRF primitive, we test whether internal services accept our requests. We replay and re-scope tokens across services, probe for services with no authentication at all, and test the message queues and event buses that often carry commands with no identity attached.

SSRF as a pivot

Server-side request forgery deserves its own note in a microservices context. In a monolith an SSRF might read a local file. In a mesh it can reach every internal service, the cloud metadata endpoint, and the secrets they hand out. We chain SSRF into lateral movement to show the true blast radius, not just the initial bug.

Distributed systems leak credentials in places a monolith never had: build arguments baked into image layers, environment variables dumped in logs, and configuration blobs shipped in the front-end bundle. We inspect the artifacts for secrets that turn a small foothold into full access.

You get a report that maps each finding to the service and the attack path, so remediation lands with the right team. After fixes ship, we retest the same paths for free to confirm the boundary now holds.

The most common serious finding. A service was built assuming only trusted siblings would ever call it, so it checks nothing. Reach it through the gateway, an SSRF, or a flat network, and it answers freely. Internal does not mean unreachable, and unreachable is not a control.

One service enforces the audience and scope claims, another does not. A token issued for a limited role is accepted with full privilege somewhere else in the mesh. Because the services look independent, this gap survives reviews that check each service on its own but never compare them.

Gateways often add headers like a user identity or role after authenticating a caller, and downstream services trust them. If a service can be reached without passing through the gateway, or the gateway fails to strip an incoming copy of that header, an attacker sets their own identity and the backend believes it.

A single SSRF in one service becomes a key to the whole cluster: internal APIs, the cloud metadata service, and the credentials it returns. We report the chain, because the severity of an SSRF in a mesh is defined by where it can reach, not by the bug in isolation.

Database passwords in a container build argument, an API key in an environment variable printed to logs, a base64 config blob in a bundle that names an internal API. These turn a minor foothold into total compromise, and they are easy to miss without looking at the artifacts directly.

For SOC 2, testing service-to-service trust shows the controls over customer data hold across the whole system, not just the front door. Under GDPR, a service that leaks personal data to an unauthenticated internal caller is an exposure, and proving those paths are closed demonstrates appropriate technical measures. Financial-sector clients under DORA can bring the distributed architecture into their threat-led testing scope.