Newell Brands DYMO Connect Desktop improper file path validation

The LoadImageAsPngBase64 endpoint of the Newell Brands DYMO Connect Desktop local web service accepts a file path parameter without adequate validation, allowing a crafted path to read arbitrary image files from the host filesystem outside the intended scope. Fixed in 1.6.2. The fix limits access by file extension only, not by directory - arbitrary-location reads of files with an allowed image extension remain possible by design (accepted residual risk).