PostScript is a programming language introduced by Adobe for image and text printing. Although this language is not well known, it is indispensable for printing. We have studied PostScript and GhostScript (an engine of PostScript) since last year. And we found several interesting security vulnerabilities in them. In this talk, we first introduce the grammar specification of PostScript and discuss the security weaknesses of this language. After that, we show several vulnerabilities of GhostScript that can cause arbitrary file read, arbitrary code execution and sandbox escape. In addition, we extend our PostScript security study to other well-known image processing software (e.g., ImageMagick, Evince) used GhostScript engine. The result shows that even the latest version of these software still have 0-day vulnerabilities for PostScript language processing.