A stack-based buffer over-read exists in FoFiTrueType::dumpString in fofi/FoFiTrueType.cc in Xpdf 4.01.01. It can, for example, be triggered by sending crafted TrueType data in a PDF document to the pdftops tool. It might allow an attacker to cause Denial of Service or leak memory data into dump content.
https://lists.debian.org/debian-lts-announce/2019/06/msg00002.html