CWE-49: Path Equivalence: 'filename/' (Trailing Slash)

Source-backed guidance

Additional facts reviewed against primary or authoritative security sources.

Verify controls for CWE-49 with SSDF evidence

Use NIST SSDF verification and vulnerability-response practices to detect CWE-49, Path Equivalence: 'filename/' (Trailing Slash), 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

Make elimination of CWE-49 a product outcome

Apply CISA's Secure by Design principle of taking ownership of customer security outcomes to CWE-49, Path Equivalence: 'filename/' (Trailing Slash). Put the weakness in the product threat model and security roadmap, fund class-level design and platform changes, prefer safe defaults and reusable guardrails, and publish measurable progress. Do not transfer the primary burden to customer configuration when the manufacturer can remove or contain the root cause in the product.

Shifting the Balance of Cybersecurity Risk: Secure by Design Software — Cybersecurity and Infrastructure Security Agency

Connect Path Equivalence: 'filename/' (Trailing Slash) to documented attack evidence

Recorded impacts include Read Files or Directories, and Modify Files or Directories; observed examples include CVE-2002-0253, CVE-2001-0446, and CVE-2004-0334; related weaknesses include CWE-41, and CWE-162. Use these source-defined anchors to turn CWE-49 into implementation, review, and verification checks for the affected component.

CWE-49: Path Equivalence: 'filename/' (Trailing Slash) — MITRE CWE

Apply precise root-cause mapping to CWE-49

Apply MITRE's full root-cause mapping guidance when using CWE-49, Path Equivalence: 'filename/' (Trailing Slash). 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-49 with root-cause mapping checks

Apply MITRE's root-cause mapping quick tips to CWE-49, Path Equivalence: 'filename/' (Trailing Slash). 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-49: Path Equivalence: 'filename/' (Trailing Slash)?+

CWE-49: Path Equivalence: 'filename/' (Trailing Slash) is a Common Weakness Enumeration (CWE) entry maintained by MITRE. The product accepts path input in the form of trailing slash ('filedir/') without appropriate validation, which can lead to ambiguous path resolution and allow an attacker to traverse the file system to unintended locations or access arbitrary files.

What are the security consequences of Path Equivalence: 'filename/' (Trailing Slash)?+

If exploited, CWE-49 (Path Equivalence: 'filename/' (Trailing Slash)) it can compromise Confidentiality and Integrity, leading to outcomes such as Read Files or Directories and Modify Files or Directories.

Which programming languages are affected by Path Equivalence: 'filename/' (Trailing Slash)?+

CWE-49 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 Path Equivalence: 'filename/' (Trailing Slash)?+

MITRE documents real CVEs mapped to CWE-49, including CVE-2002-0253, CVE-2001-0446, CVE-2004-0334, CVE-2001-0893 and CVE-2001-0892. 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-49 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-49: Path Equivalence: 'filename/' (Trailing Slash)

Technical Details

Applicable To

Security Consequences

Scope

Impact

Mitigation Strategies

Detection Methods

Code Examples & CVEs

Observed CVE Examples (6)

CWE Relationships

Parent Weaknesses