If an image had not loaded correctly (such as when it is not actually an image), it could be dragged and dropped cross-domain, resulting in a cross-origin information leak. This vulnerability affects Firefox < 71.
71.0+build5-0ubuntu0.16.04.171.0+build5-0ubuntu0.18.04.138.8.0~repack1-0ubuntu138.8.0~repack1-0ubuntu338.8.0~repack1-0ubuntu452.3.1-0ubuntu352.3.1-7fakesync152.8.1-0ubuntu0.18.04.152.9.1-0ubuntu0.18.04.171.0+build5-0ubuntu152.9.1-1build152.9.1-1ubuntu3Exploitability
AV:NAC:LPR:NUI:RScope
S:CImpact
C:HI:NA:NCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N