CWE-771: Missing Reference to Active Allocated Resource

Source-backed guidance

Additional facts reviewed against primary or authoritative security sources.

Verify controls for CWE-771 with SSDF evidence

Use NIST SSDF verification and vulnerability-response practices to detect CWE-771, Missing Reference to Active Allocated Resource, 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

Apply Resource Limitation controls for Missing Reference to Active Allocated Resource

MITRE associates mitigation with Operation, and Architecture and Design; the listed strategies include Resource Limitation; documented detection approaches include Automated Static Analysis. Use these source-defined anchors to turn CWE-771 into implementation, review, and verification checks for the affected component.

CWE-771: Missing Reference to Active Allocated Resource — MITRE CWE

Triage CWE-771 against known exploitation evidence

Use CISA's Known Exploited Vulnerabilities catalog to test whether a vulnerability mapped to CWE-771, Missing Reference to Active Allocated Resource, 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-771

Apply MITRE's full root-cause mapping guidance when using CWE-771, Missing Reference to Active Allocated Resource. 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-771 with root-cause mapping checks

Apply MITRE's root-cause mapping quick tips to CWE-771, Missing Reference to Active Allocated Resource. 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-771: Missing Reference to Active Allocated Resource?+

CWE-771: Missing Reference to Active Allocated Resource is a Common Weakness Enumeration (CWE) entry maintained by MITRE. The product does not properly maintain a reference to a resource that has been allocated, which prevents the resource from being reclaimed. This does not necessarily apply in languages or frameworks that automatically perform garbage collection, since the removal of all references may act as a signal that the resource is ready to be reclaimed.

What are the security consequences of Missing Reference to Active Allocated Resource?+

If exploited, CWE-771 (Missing Reference to Active Allocated Resource) it can compromise Availability, leading to outcomes such as DoS: Resource Consumption (Other).

Which programming languages are affected by Missing Reference to Active Allocated Resource?+

CWE-771 commonly affects Not Language-Specific. 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-771 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-771: Missing Reference to Active Allocated Resource

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