Stirling-PDF is a locally hosted web application that allows you to perform various operations on PDF files. Prior to version 0.45.0, Stirling-PDF is vulnerable to SSRF-induced arbitrary file read. WeasyPrint redefines a set of HTML tags, including img, embed, object, and others. The references to several files inside, allow the attachment of content from any webpage or local file to a PDF. This allows the attacker to read any file on the server, including sensitive files and configuration files. All users utilizing this feature will be affected. This issue has been patched in version 0.45.0.
The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination.