PDFium in Google Chrome before 53.0.2785.89 on Windows and OS X and before 53.0.2785.92 on Linux mishandles timers, which allows remote attackers to cause a denial of service (use-after-free) or possibly have unspecified other impact via a crafted PDF document, related to fpdfsdk/javascript/JS_Object.cpp and fpdfsdk/javascript/app.cpp.