A content security policy (CSP) “frame-ancestors” directive containing origins with paths allows for comparisons against those paths instead of the origin. This results in a cross-origin information leak of this path information. This vulnerability affects Firefox < 55.
[
{
"product": "Firefox",
"vendor": "Mozilla",
"versions": [
{
"lessThan": "55",
"status": "affected",
"version": "unspecified",
"versionType": "custom"
}
]
}
]