* Take the SSRF address policy from surfguard instead of keeping our own copy
Four other apps carried this same classification and the five had drifted into
four different ideas of what "internal" means. It now comes from the surfguard
gem, which is their union. resolve and Violation keep their shapes, so the
opengraph callers are unchanged.
Two verdicts change.
SIIT (::ffff:0:0:0/96) is now recognised. It is the third way an IPv4 address
rides inside an IPv6 one and the only one Ruby has no predicate for --
ipv4_mapped?, ipv4_compat?, private?, loopback? and link_local? are all false
for ::ffff:0:a9fe:a9fe, so it fell through to the IPv6 branch unrecognised and
reached the metadata endpoint. Note the extra group: ::ffff:0:0:0/96 is not the
IPv4-mapped ::ffff:0:0/96 the guard already refused, and the two do not overlap.
The RFC 8215 local-use NAT64 block is now refused whole rather than decoded.
Reading its low 32 bits as an embedded IPv4 is only correct for a /96 Pref64;
the block can host any length from /32 to /96 and the position is not
recoverable from the address alone (RFC 6052 2.2), so the decode reads the
wrong octets. It is never globally routed, so refusing it costs nothing. The
well-known /96 is still decoded and re-checked, so DNS64 for public sites on
IPv6-only hosts keeps working.
Resolution moves from Resolv.getaddress to Resolv.getaddresses, so the guard
sees every address a host answers with rather than only the first.
* Distinguish a DNS lookup failure from a private-IP block in the guard
Advance the surfguard pin so resolve_public_ips raises Unresolvable when a
host resolves to nothing and returns an empty list only when it resolves to a
blocked address. The shim lets Unresolvable propagate as a lookup failure --
matching the old Resolv.getaddress behavior -- and reserves Violation for a
resolved-but-blocked address, so a transient DNS miss is no longer reported as
an SSRF attempt.
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
Jeremy Daer
Mike Dalessio
Donal McBreen
Stanko K.R.