Blazor работает на WebAssembly.
Это такая потенциально опасная дыра, что просто жуть.
Например, исследование пару лет назад
И сразу сносятся всякие защитные ограничения.
Например,
Our Security Team discovered a new type of Auto-Redirect attack using WASM to run Javascript code which will eventually lead the user, without any interaction, to a non-desired landing page.
In one of our previous posts we discussed Sandboxing, why it was created and how it was supposed to be a safer way to run Iframes. Unfortunately, we’ve seen how attackers are able to easily bypass it by serving code in a cross-origin platform, and leverage the ability of code served in the same origin platform by navigating through Sandboxing.
https://www.geoedge.com/webassembly-a-new-attack-uncovered/