CWE-656: Reliance on Security Through Obscurity

Extended Description

This reliance on "security through obscurity" can produce resultant weaknesses if an attacker is able to reverse engineer the inner workings of the mechanism. Note that obscurity can be one small part of defense in depth, since it can create more work for an attacker; however, it is a significant risk if used as the primary means of protection.

Source-backed guidance

Additional facts reviewed against primary or authoritative security sources.

Verify controls for CWE-656 with SSDF evidence

Use NIST SSDF verification and vulnerability-response practices to detect CWE-656, Reliance on Security Through Obscurity, 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 Security Through Obscurity during Architecture and Design

MITRE associates mitigation with Architecture and Design; recorded impacts include Other; observed examples include CVE-2006-6588, CVE-2006-7142, and CVE-2005-4002. Use these source-defined anchors to turn CWE-656 into implementation, review, and verification checks for the affected component.

CWE-656: Reliance on Security Through Obscurity — MITRE CWE

Triage CWE-656 against known exploitation evidence

Use CISA's Known Exploited Vulnerabilities catalog to test whether a vulnerability mapped to CWE-656, Reliance on Security Through Obscurity, 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-656

Apply MITRE's full root-cause mapping guidance when using CWE-656, Reliance on Security Through Obscurity. 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-656 with root-cause mapping checks

Apply MITRE's root-cause mapping quick tips to CWE-656, Reliance on Security Through Obscurity. 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-656: Reliance on Security Through Obscurity?+

CWE-656: Reliance on Security Through Obscurity is a Common Weakness Enumeration (CWE) entry maintained by MITRE. The product uses a protection mechanism whose strength depends heavily on its obscurity, such that knowledge of its algorithms or key data is sufficient to defeat the mechanism. This reliance on "security through obscurity" can produce resultant weaknesses if an attacker is able to reverse engineer the inner workings of the mechanism. Note that obscurity can be one small part of defense in depth, since it can create more work for an attacker; however, it is a significant risk if used as the primary means of protection.

What are the security consequences of Reliance on Security Through Obscurity?+

If exploited, CWE-656 (Reliance on Security Through Obscurity) it can compromise Confidentiality, Integrity, Availability and Other, leading to outcomes such as Other.

How do you prevent or mitigate Reliance on Security Through Obscurity?+

Recommended mitigations for CWE-656 include: Always consider whether knowledge of your code or design is sufficient to break it. Reverse engineering is a highly successful discipline, and financially feasible for motivated adversaries. Black-box techniques are established for binary analysis of executables that use obfuscation, runtime analysis of proprietary protocols, inferring file formats, and others. When available, use publicly-vetted algorithms and procedures, as these are more likely to undergo more extensive security analysis and testing. This is especially the case with encryption and authentication.

Which programming languages are affected by Reliance on Security Through Obscurity?+

CWE-656 commonly affects Not Language-Specific. Note that weaknesses are often language-agnostic patterns, so secure coding practices apply broadly.

What are real-world examples of Reliance on Security Through Obscurity?+

MITRE documents real CVEs mapped to CWE-656, including CVE-2006-6588, CVE-2006-7142, CVE-2005-4002 and CVE-2006-4068. You can look up the full details of each CVE, including CVSS scores and remediation guidance, on our CVE Lookup tool.

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

A CWE (Common Weakness Enumeration) like CWE-656 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-656: Reliance on Security Through Obscurity

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Observed CVE Examples (4)

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