In Xpdf 4.01.01, a heap-based buffer over-read could be triggered in strncpy from FoFiType1::parse in fofi/FoFiType1.cc because it does not ensure the source string has a valid length before making a fixed-length copy. It can, for example, be triggered by sending a crafted PDF document to the pdftotext tool. It allows an attacker to use a crafted pdf file to cause Denial of Service or an information leak, or possibly have unspecified other impact.
The product reads data past the end, or before the beginning, of the intended buffer.