CWE-547: Use of Hard-coded, Security-relevant Constants

Extended Description

If the developer does not find all occurrences of the hard-coded constants, an incorrect policy decision may be made if one of the constants is not changed. Making changes to these values will require code changes that may be difficult or impossible once the system is released to the field. In addition, these hard-coded values may become available to attackers if the code is ever disclosed.

Code Examples & CVEs

Demonstrative Examples

The usage of symbolic names instead of hard-coded constants is preferred.

The following is an example of using a hard-coded constant instead of a symbolic name.

BadC

char buffer[1024];...fgets(buffer, 1024, stdin);

The usage of symbolic names instead of hard-coded constants is preferred.

The following is an example of using a hard-coded constant instead of a symbolic name.

GoodC

enum { MAX_BUFFER_SIZE = 1024 };...char buffer[MAX_BUFFER_SIZE];...fgets(buffer, MAX_BUFFER_SIZE, stdin);

Source-backed guidance

Additional facts reviewed against primary or authoritative security sources.

Verify controls for CWE-547 with SSDF evidence

Use NIST SSDF verification and vulnerability-response practices to detect CWE-547, Use of Hard-coded, Security-relevant Constants, 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 Use of Hard-coded, Security-relevant Constants during Implementation

MITRE associates mitigation with Implementation; documented detection approaches include Automated Static Analysis; recorded impacts include Varies by Context, Quality Degradation, and Reduce Maintainability. Use these source-defined anchors to turn CWE-547 into implementation, review, and verification checks for the affected component.

CWE-547: Use of Hard-coded, Security-relevant Constants — MITRE CWE

Triage CWE-547 against known exploitation evidence

Use CISA's Known Exploited Vulnerabilities catalog to test whether a vulnerability mapped to CWE-547, Use of Hard-coded, Security-relevant Constants, 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-547

Apply MITRE's full root-cause mapping guidance when using CWE-547, Use of Hard-coded, Security-relevant Constants. 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-547 with root-cause mapping checks

Apply MITRE's root-cause mapping quick tips to CWE-547, Use of Hard-coded, Security-relevant Constants. 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-547: Use of Hard-coded, Security-relevant Constants?+

CWE-547: Use of Hard-coded, Security-relevant Constants is a Common Weakness Enumeration (CWE) entry maintained by MITRE. The product uses hard-coded constants instead of symbolic names for security-critical values, which increases the likelihood of mistakes during code maintenance or security policy change. If the developer does not find all occurrences of the hard-coded constants, an incorrect policy decision may be made if one of the constants is not changed. Making changes to these values will require code changes that may be difficult or impossible once the system is released to the field. In addition, these hard-coded values may become available to attackers if the code is ever disclosed.

What are the security consequences of Use of Hard-coded, Security-relevant Constants?+

If exploited, CWE-547 (Use of Hard-coded, Security-relevant Constants) it can compromise Other, leading to outcomes such as Varies by Context, Quality Degradation and Reduce Maintainability.

How do you prevent or mitigate Use of Hard-coded, Security-relevant Constants?+

Recommended mitigations for CWE-547 include: Avoid using hard-coded constants. Configuration files offer a more flexible solution.

Which programming languages are affected by Use of Hard-coded, Security-relevant Constants?+

CWE-547 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-547 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-547: Use of Hard-coded, Security-relevant Constants

Extended Description

Technical Details

Applicable To

Security Consequences

Scope

Impact

Mitigation Strategies

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Detection Methods