Implement non-vulnerable IMAGING FILTERS for embedded PICTURES (in Writer etc.). Do not change the images contained in the ODT-files, but apply filters Just-In-Time while showing the images in Libreoffice (Writer) Maybe this could be done with ImageMagick/GraphicsMagick ... Even Microsoft Word has simple image filters for changing the brightness and saturation of embedded images ...
I think it would be good to have some at least basic features to change pictures like the mentioned brightness. In LO we have already a few features like rotating, mirroring and cutting, but more features would be good. Regarding the "Edit with External Tool" option it would be good to have the option to choose the tool from a list of available tools in order to edit the picture. reproducible with LO 4.1.4.2 (Win7 Home, 64bit)