A vulnerability has been found in FederatedAI FATE up to 2.2.0. This affects the function QueuePushReqStreamObserver.initEggroll of the file java/osx/osx-broker/src/main/java/org/fedai/osx/broker/grpc/QueuePushReqStreamObserver.java of the component OSX Broker. Such manipulation of the argument rollSiteSessionId/dstRole/dstPartyId leads to exposure of data element to wrong session. The attack can be executed remotely. A high complexity level is associated with this attack. It is indicated that the exploitability is difficult. The exploit has been disclosed to the public and may be used. The pull request to fix this issue awaits acceptance.
The product does not sufficiently enforce boundaries between the states of different sessions, causing data to be provided to, or used by, the wrong session.
Data can “bleed” from one session to another through member variables of singleton objects, such as Servlets, and objects from a shared pool. In the case of Servlets, developers sometimes do not understand that, unless a Servlet implements the SingleThreadModel interface, the Servlet is a singleton; there is only one instance of the Servlet, and that single instance is used and re-used to handle multiple requests that are processed simultaneously by different threads. A common result is that developers use Servlet member fields in such a way that one user may inadvertently see another user’s data. In other words, storing user data in Servlet member fields introduces a data access race condition.