CWE-487: Reliance on Package-level Scope

Code Examples & CVEs

Demonstrative Examples

The following example demonstrates the weakness.

BadJava

package math;public class Lebesgue implements Integration{                         public final Static String youAreHidingThisFunction(functionToIntegrate){                                                                 return ...;                            }                      }

Source-backed guidance

Additional facts reviewed against primary or authoritative security sources.

Verify controls for CWE-487 with SSDF evidence

Use NIST SSDF verification and vulnerability-response practices to detect CWE-487, Reliance on Package-level Scope, throughout the product lifecycle. Derive review questions, static or dynamic checks, and negative tests from the CWE's causal behavior; define the components and lifecycle stages each check covers; and retain findings with enough evidence to distinguish the root cause from symptoms and impacts. Track escapes and false negatives, then improve the verification plan after every confirmed occurrence.

NIST SP 800-218 Secure Software Development Framework — National Institute of Standards and Technology

Address Reliance on Package-level Scope during Architecture and Design

MITRE associates mitigation with Architecture and Design, and Implementation; documented detection approaches include Automated Static Analysis; recorded impacts include Read Application Data, and Modify Application Data. Use these source-defined anchors to turn CWE-487 into implementation, review, and verification checks for the affected component.

CWE-487: Reliance on Package-level Scope — MITRE CWE

Triage CWE-487 against known exploitation evidence

Use CISA's Known Exploited Vulnerabilities catalog to test whether a vulnerability mapped to CWE-487, Reliance on Package-level Scope, has evidence of exploitation in the wild. Confirm the CVE-to-CWE root-cause mapping independently before attaching the example, then capture the affected product, required action, and remediation deadline. A missing KEV match is not evidence that the weakness is unexploited, and a KEV entry must not be generalized to every occurrence of this CWE.

Known Exploited Vulnerabilities Catalog — Cybersecurity and Infrastructure Security Agency

Apply precise root-cause mapping to CWE-487

Apply MITRE's full root-cause mapping guidance when using CWE-487, Reliance on Package-level Scope. Separate weakness language from attacker prerequisites and technical impact, check the entry's abstraction and vulnerability-mapping notes, and prefer the most specific Base or Variant supported by the evidence. Record the rejected alternatives and require an independent review before the mapping is used for remediation trends or program metrics.

CVE to CWE Root Cause Mapping Guidance — MITRE CWE

Validate CWE-487 with root-cause mapping checks

Apply MITRE's root-cause mapping quick tips to CWE-487, Reliance on Package-level Scope. Confirm the finding describes the causal weakness rather than an impact or attack pattern, compare the abstraction and mapping notes with plausible alternatives, and have a second reviewer challenge the selection. Preserve the evidence and reasoning so recurring defects can be measured against one consistent identifier.

CVE to CWE Root Cause Mapping Quick Tips — MITRE CWE

Frequently Asked Questions

What is CWE-487: Reliance on Package-level Scope?+

CWE-487: Reliance on Package-level Scope is a Common Weakness Enumeration (CWE) entry maintained by MITRE. 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.

What are the security consequences of Reliance on Package-level Scope?+

If exploited, CWE-487 (Reliance on Package-level Scope) it can compromise Confidentiality and Integrity, leading to outcomes such as Read Application Data and Modify Application Data.

How do you prevent or mitigate Reliance on Package-level Scope?+

Recommended mitigations for CWE-487 include: Data should be private static and final whenever possible. This will assure that your code is protected by instantiating early, preventing access and tampering.

Which programming languages are affected by Reliance on Package-level Scope?+

CWE-487 commonly affects Java. Note that weaknesses are often language-agnostic patterns, so secure coding practices apply broadly.

What is the difference between a CWE and a CVE?+

A CWE (Common Weakness Enumeration) like CWE-487 describes a category of software weakness — the underlying flaw type. A CVE (Common Vulnerabilities and Exposures) identifies a specific, real-world vulnerability in a particular product. In short, a CWE is the kind of mistake, and a CVE is an instance of that mistake being found in software.

CWE-487: Reliance on Package-level Scope

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