3 10-year-old apps with the "KnownVuln" flag still in the main repository

• cx.hell.android.pdfview (APV PDF Viewer) - latest release: 2013
• io.github.droidapps.pdfreader (PDF Reader) - latest release: 2014
• it.iiizio.epubator (ePUBator) - latest release: 2015