CVE-2017-18355 in Rendertron
Summary
by MITRE
Installed packages are exposed by node_modules in Rendertron 1.0.0, allowing remote attackers to read absolute paths on the server by examining the "_where" attribute of package.json files.
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Analysis
by VulDB Data Team • 06/19/2023
The vulnerability identified as CVE-2017-18355 resides within Rendertron version 1.0.0, a server-side rendering solution for web applications that converts dynamic content into static HTML for improved performance and SEO. This flaw represents a critical information disclosure issue that arises from how the application handles package metadata during dependency resolution. The vulnerability specifically manifests through the exposure of absolute file paths stored in the "_where" attribute of package.json files within the node_modules directory structure. When Rendertron processes requests, it inadvertently includes this sensitive path information in its response, creating a direct avenue for remote attackers to discover the underlying server filesystem structure.
The technical implementation of this vulnerability stems from improper handling of node.js package management metadata within the Rendertron framework. During the package resolution process, the application constructs response data that includes the "_where" field from package.json files, which contains absolute paths to the package installation directories. This metadata field is typically used internally by npm for dependency management but should not be exposed to external clients. The flaw occurs because Rendertron fails to sanitize or filter this information before including it in HTTP responses, effectively leaking server-side path information that could be leveraged for further exploitation.
The operational impact of CVE-2017-18355 extends beyond simple information disclosure, as it provides attackers with critical reconnaissance data that can inform subsequent attack vectors. The exposed absolute paths reveal the server's directory structure, potentially exposing sensitive locations such as configuration files, source code repositories, or other potentially vulnerable directories. This information disclosure aligns with CWE-200, which categorizes the exposure of sensitive information to unauthorized actors. Attackers can use this path information to plan more sophisticated attacks, including directory traversal attempts, privilege escalation, or targeted exploitation of other vulnerabilities present in the server environment. The vulnerability particularly affects environments where Rendertron is deployed with default configurations, making it accessible to any remote attacker with basic network connectivity.
This vulnerability demonstrates a clear violation of secure coding practices and information hiding principles that should be fundamental to web application security. The exposure of absolute paths represents a classic example of insufficient output filtering, where application data is not properly sanitized before being transmitted to external parties. From an ATT&CK framework perspective, this vulnerability maps to the reconnaissance phase where adversaries gather information about the target system. The ability to extract filesystem paths through HTTP responses provides attackers with essential infrastructure intelligence that can be used for privilege escalation or lateral movement within the network. Organizations using Rendertron 1.0.0 should immediately implement mitigations including code-level sanitization of package metadata, configuration changes to prevent path exposure, and comprehensive security audits of all dependencies to ensure similar vulnerabilities are not present in other components of their software supply chain.