libreoffice: Integer overflow leading to buffer overflow by processing invalid Escher graphics records length in the Powerpoint documents

Integer overflow in filter/source/msfilter/msdffimp.cxx in OpenOffice.org OOo 3.3, 3.4 Beta, and possibly earlier, and LibreOffice before 3.5.3, allows remote attackers to cause a denial of service crash and possibly execute arbitrary code via the length of an Escher graphics record in a PowerPoi...