CWE-487

Base Abstraction Level
Pillar — Highest-level weakness category
Class — Abstract, language-independent
Base — Specific enough to detect
Variant — Tied to specific technology
Compound — Requires multiple weaknesses Incomplete MITRE CWE Status
Stable — Fully reviewed and complete
Draft — Under development, may change
Incomplete — Partially defined by MITRE
Deprecated — No longer recommended
Obsolete — Replaced by another CWE Exploit: Medium
Reliance on Package-level Scope

Description

Java packages are not inherently closed; therefore, relying on them for code security is not a good practice.

The purpose of package scope is to prevent accidental access by other parts of a program. This is an ease-of-software-development feature but not a security feature.

Consequences

Confidentiality — Read Application Data

Any data in a Java package can be accessed outside of the Java framework if the package is distributed.

Integrity — Modify Application Data

The data in a Java class can be modified by anyone outside of the Java framework if the package is distributed.

Mitigations

Phase: Architecture and Design, Implementation

Data should be private static and final whenever possible. This will assure that your code is protected by instantiating early, preventing access and tampering.

Detection

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.)