Spring Cloud Gateway Server Webflux may be vulnerable to Spring Environment property modification.

An application should be considered vulnerable when all the following are true:

The application is using Spring Cloud Gateway Server Webflux (Spring Cloud Gateway Server WebMVC is not vulnerable). Spring Boot actuator is a dependency. The Spring Cloud Gateway Server Webflux actuator web endpoint is enabled via management.endpoints.web.exposure.include=gateway. The actuator endpoints are available to attackers. The actuator endpoints are unsecured.

Spring Cloud Gateway Server forwards the X-Forwarded-For and Forwarded headers from untrusted proxies.

In spring cloud gateway versions prior to 3.1.1+ , applications that are configured to enable HTTP2 and no key store or trusted certificates are set will be configured to use an insecure TrustManager. This makes the gateway able to connect to remote services with invalid or custom certificates.

Applications using Spring Cloud Gateway are vulnerable to specifically crafted requests that could make an extra request on downstream services. Users of affected versions should apply the following mitigation: 3.0.x users should upgrade to 3.0.5+, 2.2.x users should upgrade to 2.2.10.RELEASE or newer.