CWE-488 Exposure of Data Element to Wrong Session

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.

• Confidentiality: Read Application Data — Data can "bleed" from one session to another through member variables of singleton objects, such as Servlets, and objects from a shared pool. Storing user data in Servlet member fields introduces a data access race condition.

• [Architecture and Design] Protect the application's sessions from information leakage. Make sure that a session's data is not used or visible by other sessions. • [Testing] Use a static analysis tool to scan the code for information leakage vulnerabilities (e.g. Singleton Member Field). • [Architecture and Design] In a multithreading environment, storing user data in Servlet member fields introduces a data access race condition. Do not use member fields to store information in the Servlet.

• Automated Static Analysis: Automated static analysis, commonly referred to as Static Application Security Testing (SAST), can find some instances of this weakness by analyzing source code (or binary/compiled code) without having to execute it. Typically, this is done by building a model of data flow and control flow, then searching for potentially-vulnerable patterns that connect "sources" (origins of input) with "sinks" (destinations where the data interacts with external components, a lower layer such as the OS, etc.)