The inline sidebar apps hand their origins to the proxy through a
client-written cookie, which the proxy merges into `frame-src`. Any
same-site sibling host could set that cookie too. Over HTTPS the cookie
is now `__Host-bulwark_app_frame_origins`, which only this exact host
can set, and the proxy ignores the unprefixed name there. Plain HTTP
(local development) keeps the old name.
The URL guard behind fetch-ical, OAuth discovery, branding and the
server-side JMAP fetches blocked only the single address 127.0.0.1 plus
the RFC 1918, link-local and ULA subnets. Any logged-in user could make
the server fetch 127.0.0.2, 100.64.0.0/10, 198.18.0.0/15, multicast,
reserved space or a NAT64/6to4/Teredo address that wraps an internal
IPv4 address.
The telemetry guard already rejected all of these (GHSA-m7j8), so its
range check moves to `lib/security/ip-ranges.ts` and both guards use it.
`guardedLookup` inherits the wider list, so the connect-time rebinding
check covers the new ranges too.
Linus Rath