Ruby on Rails Action View Path Traversal (CVE-2019-5418)

Historical catalog analysis: CISA added this entry on July 07, 2025. The entry reflects catalog information retrieved on August 31, 2026, not a snapshot archived on the inclusion date. Check current vendor guidance before acting.

What the vulnerability is

CVE-2019-5418 is a path traversal vulnerability (CWE-22) located within the Action View component of the Ruby on Rails framework. The flaw allows an attacker to disclose the contents of arbitrary files residing on the target server.

Exposure and applicability

Exposure occurs when a Ruby on Rails application utilizes the render file: call in conjunction with specially crafted accept headers provided in the request. This combination enables the rendering and subsequent disclosure of sensitive files from the underlying filesystem. Organizations running Ruby on Rails environments that employ these specific Action View functions are susceptible to this exposure.

Remediation priorities

Based on our analysis, vulnerability management teams should prioritize the following actions to reduce exposure:

1. Identify Affected Assets: Inventory all Ruby on Rails deployments and specifically audit code for the use of render file: within the Action View component.
2. Apply Vendor Mitigations: Deploy the official patches or mitigations provided by the Rails project to address the path traversal logic.
3. Cloud Service Alignment: For assets hosted in cloud environments, align remediation efforts with BOD 22-01 guidance where applicable.
4. Decommissioning: If vendor mitigations cannot be applied or are unavailable for a specific legacy version, the product should be discontinued to eliminate the risk.

How to validate remediation

Verification must go beyond a simple version check, as a deployed update does not inherently guarantee that the vulnerability is mitigated in the active environment. Defenders should verify remediation through:

• Configuration Audit: Confirming that the patched version of Action View is actively loaded and running in production.
• Functional Testing: Using authorized security testing to attempt a file disclosure request using crafted accept headers to ensure the system no longer renders arbitrary files.

Limits and open questions

While patching reduces the likelihood of exploitation, residual risk may remain if custom extensions to Action View introduce similar path traversal patterns. The source does not provide information regarding whether this vulnerability has been utilized in known ransomware campaigns; this status remains unknown.

Source and editorial note

CVE-2019-5418: Rails Ruby on Rails Path Traversal Vulnerability · Source date: July 07, 2025 · Retrieved August 31, 2026.

Material facts are tied to the cited primary source. Recommendations are independent defensive analysis unless attributed to the source. Confirm consequential decisions against current authoritative guidance.

Archive date: July 10, 2025. The displayed post date is assigned three days after the source date to organize this retrospective archive; it does not mean this site published the analysis then. First published by this site: October 09, 2026 at 00:49 UTC.

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