JavaScript-based PDF Viewers, Cross Site Scripting, and PDF files

&#xA; ❗️Disclosure: I worked at Smallpdf from January to November 2021. In that period, Smallpdf used PDFTron WebViewer SDK (now Apryse PDF WebViewer) to render PDF files in the browser. This information was public . &#xA; Interview and first XSS in PDFTron WebViewer &#xA; In October 2020, I started my job interview with Smallpdf for a Cloud Security Engineer position. During the interview…