Spring Framework, version 5.1, versions 5.0.x prior to 5.0.10, versions 4.3.x prior to 4.3.20, and older unsupported versions on the 4.2.x branch provide support for range requests when serving static resources through the ResourceHttpRequestHandler, or starting in 5.0 when an annotated controller returns an org.springframework.core.io.Resource. A malicious user (or attacker) can add a range header with a high number of ranges, or with wide ranges that overlap, or both, for a denial of service attack. This vulnerability affects applications that depend on either spring-webmvc or spring-webflux. Such applications must also have a registration for serving static resources (e.g. JS, CSS, images, and others), or have an annotated controller that returns an org.springframework.core.io.Resource. Spring Boot applications that depend on spring-boot-starter-web or spring-boot-starter-webflux are ready to serve static resources out of the box and are therefore vulnerable.

Spring Framework, versions 5.0 prior to 5.0.5 and versions 4.3 prior to 4.3.15 and older unsupported versions, allow applications to expose STOMP over WebSocket endpoints with a simple, in-memory STOMP broker through the spring-messaging module. A malicious user (or attacker) can craft a message to the broker that can lead to a remote code execution attack.

Spring Framework, versions 5.0 prior to 5.0.5 and versions 4.3 prior to 4.3.15 and older unsupported versions, allow applications to configure Spring MVC to serve static resources (e.g. CSS, JS, images). When static resources are served from a file system on Windows (as opposed to the classpath, or the ServletContext), a malicious user can send a request using a specially crafted URL that can lead a directory traversal attack.

Spring Framework, versions 5.0 prior to 5.0.5 and versions 4.3 prior to 4.3.15 and older unsupported versions, provide client-side support for multipart requests. When Spring MVC or Spring WebFlux server application (server A) receives input from a remote client, and then uses that input to make a multipart request to another server (server B), it can be exposed to an attack, where an extra multipart is inserted in the content of the request from server A, causing server B to use the wrong value for a part it expects. This could to lead privilege escalation, for example, if the part content represents a username or user roles.