CTI-Transmute is affected by a server-side request forgery vulnerability in the evaluation report PDF-generation functionality.
User-controlled CTI content, including conversion names, descriptions, and comments, is converted from Markdown to HTML and rendered as a PDF using WeasyPrint. Before the patch, the renderer used WeasyPrint’s default URL-fetching behavior without restricting the protocols or destinations that could be referenced by the generated HTML.
An attacker able to supply content included in an evaluation report could inject crafted resource references using schemes such as http://, https://, or file://. When the report was rendered, CTI-Transmute could fetch these resources using the application server’s network connectivity and filesystem privileges.
Successful exploitation could allow an attacker to:
access services available only from the CTI-Transmute server or its internal network; probe internal hosts and service endpoints; retrieve local files readable by the application process; and expose fetched content through the generated PDF, depending on the referenced resource type and rendering context.
The vulnerability is corrected by providing WeasyPrint with a restrictive URL fetcher that permits only self-contained data: URIs. The externally hosted Google Fonts stylesheet was also removed so that PDF generation performs no intentional network or filesystem fetches.
RansomLook contains insufficient resource validation in the analysis PDF generation functionality. Analysis documents are converted from Markdown to HTML and passed to WeasyPrint for PDF rendering. Prior to the fix, WeasyPrint used its default URL fetcher, allowing resource references contained in an analysis to be resolved without restrictions.
An authenticated attacker able to create or modify an analysis could embed crafted resource references using schemes such as file:// or http://. When the analysis was subsequently rendered as PDF, WeasyPrint would process these references with the privileges and network access of the RansomLook server.
A malicious file:// reference could cause the renderer to access arbitrary files readable by the RansomLook process, potentially exposing sensitive configuration, credentials, or other local data through rendered resources. Network URLs could cause the server to initiate requests to localhost, internal network services, or external systems, resulting in server-side request forgery (SSRF) and potentially bypassing network-level access restrictions.
The patch introduces a dedicated WeasyPrint URL fetcher that permits only data: resources, the RansomLook report logo, and files contained within the analysis asset directory. Network resources and filesystem paths outside these explicitly permitted locations are rejected.
WeasyPrint helps web developers to create PDF documents. Prior to version 68.0, a server-side request forgery (SSRF) protection bypass exists in WeasyPrint's defaulturlfetcher. The vulnerability allows attackers to access internal network resources (such as localhost services or cloud metadata endpoints) even when a developer has implemented a custom urlfetcher to block such access. This occurs because the underlying urllib library follows HTTP redirects automatically without re-validating the new destination against the developer's security policy. Version 68.0 contains a patch for the issue.