Limitations on the URIs allowed to WebExtensions by the browser.windows.create API can be bypassed when a pipe in the URL field is used within the extension to load multiple pages as a single argument. This could allow a malicious WebExtension to open privileged about: or file: locations. This vulnerability affects Firefox < 64.
[
{
"product": "Firefox",
"vendor": "Mozilla",
"versions": [
{
"lessThan": "64",
"status": "affected",
"version": "unspecified",
"versionType": "custom"
}
]
}
]