In GNOME Shell through 45.7, a portal helper can be launched automatically (without user confirmation) based on network responses provided by an adversary…

In GNOME Shell through 45.7, a portal helper can be launched automatically (without user confirmation) based on network responses provided by an adversary (e.g., an adversary who controls the local Wi-Fi network), and subsequently loads untrusted JavaScript code, which may lead to resource consumption or other impacts depending on the JavaScript code's behavior.