| 1. not all browsers are the same they are all aiming to implement the same html spec 2. there is no official standard there literally is > A context is considered secure when it meets certain minimum standards of authentication and confidentiality defined in the Secure Contexts specification https://w3c.github.io/webappsec-secure-contexts/ 3. even if there was, standards are often ignored major browsers wouldn't be major browsers if this was the case 4. what is true today can be false tomorrow standards take a long time to become standard and an even longer time to be phased out. this wouldn't sneak up on anyone 5. this is mitigation, not security this is a spec that provides a feature called "secure context". this is a security feature. it's in the name. it's in the spec. |
>5.1. Incomplete Isolation > >The secure context definition in this document does not completely isolate a "secure" view on an origin from a "non-secure" view on the same origin. Exfiltration will still be possible via increasingly esoteric mechanisms such as the contents of localStorage/sessionStorage, storage events, BroadcastChannel, and others.
>5.2. localhost > >Section 6.3 of [RFC6761] lays out the resolution of localhost. and names falling within .localhost. as special, and suggests that local resolvers SHOULD/MAY treat them specially. For better or worse, resolvers often ignore these suggestions, and will send localhost to the network for resolution in a number of circumstances. > >Given that uncertainty, user agents MAY treat localhost names as having potentially trustworthy origins if and only if they also adhere to the localhost name resolution rules spelled out in [let-localhost-be-localhost] (which boil down to ensuring that localhost never resolves to a non-loopback address).
>6. Privacy Considerations > >The secure context definition in this document does not in itself have any privacy impact. It does, however, enable other features which do have interesting privacy implications to lock themselves into contexts which ensures that specific guarantees can be made regarding integrity, authenticity, and confidentiality. > >From a privacy perspective, specification authors are encouraged to consider requiring secure contexts for the features they define.
This does not qualify as the "this" in my original comment.