and add test coverage for (un)supported file types.
The avatar and logo variants move into the models and return nil for content
types that are no longer variable, so the controllers fall back to the initials
avatar and stock logo icon instead of raising `ActiveStorage::InvariableError`.
Matches the fizzy guard: the local-use NAT64 prefix (64:ff9b:1::/48,
RFC 8215) embeds an IPv4 target in its low 32 bits just like the
well-known prefix, so run it through the same embedded-IPv4 recheck.
Local-use NAT64 to a public address now resolves (keeping unfurls
working for self-hosters on such networks) while local-use NAT64 to an
internal address stays blocked.
The local-use NAT64 prefix (64:ff9b:1::/48, RFC 8215) embeds an IPv4
target like the well-known prefix does, but at a deployment-chosen
position we can't extract, so block the whole range outright.
Also block the IPv6 benchmarking range (2001:2::/48, RFC 5180) to match
the IPv4 benchmarking block on 198.18.0.0/15.
The guard blocked the usual private, loopback, and link-local ranges (and
the IPv4-mapped/-compatible IPv6 forms), but let through NAT64, 6to4, and
Teredo addresses, which can point at an internal IPv4, and CGNAT.
Now it pulls the IPv4 out of a NAT64 address and checks that (so NAT64 to a
public site still works), blocks 6to4 and Teredo outright, and adds the
missing IPv4 and IPv6 ranges.
Adds ipv4_mapped? and ipv4_compat? checks to PrivateNetworkGuard.private_ip?
to block SSRF bypass attempts using IPv6 address formats like:
- ::ffff:169.254.169.254 (IPv4-mapped)
- ::169.254.169.254 (IPv4-compatible)
These formats could previously bypass the link_local? check since Ruby
treats them as IPv6 addresses, not IPv4.
Ref: HackerOne #3481701