allowUniversalAccessFromFileURLs property Null safety
Sets whether cross-origin requests in the context of a file scheme URL should be allowed to access content from any origin. This includes access to content from other file scheme URLs or web contexts. Note that some access such as image HTML elements doesn't follow same-origin rules and isn't affected by this setting.
Don't enable this setting if you open files that may be created or altered by external sources.
Enabling this setting allows malicious scripts loaded in a
file:// context to launch cross-site scripting attacks,
either accessing arbitrary local files including WebView cookies, app private data or even credentials used on arbitrary web sites.
The default value is