Integer overflow in Picasa3.exe in Google Picasa before 3.9.0 Build 137.69 allows remote attackers to execute arbitrary code via a long TIFF tag that triggers a heap-based buffer overflow, as demonstrated using a Canon RAW CR2 file with a long TIFF StripByteCounts tag.
https://support.google.com/picasa/answer/53209
http://www.securitytracker.com/id/1029527