Webhook and HTTP message endpoint deliveries both flow through
Postal::HTTP, which parsed the user-supplied URL and connected to its
host with no address validation. An authenticated user could point a
webhook or endpoint at a private, loopback or link-local address (e.g.
127.0.0.1, 169.254.169.254 cloud metadata, RFC1918 hosts) and make the
server issue requests into its own internal network.
Add Postal::HTTP::AddressGuard, which resolves the destination host and
rejects private/loopback/link-local/reserved/multicast IPv4 and IPv6
addresses, then pins the connection to the validated address so it cannot
be redirected via a DNS-rebinding race. Administrators can permit specific
destinations via the new postal.allowed_request_destinations config option
(hostnames or IP/CIDR ranges).
Address selection only uses families this server can actually reach so we
do not pin to an IPv6 address on a host without IPv6 connectivity; IPv4 is
preferred for predictability. HTTPEndpoint now validates that its URL is a
well-formed HTTP(S) URL with a host.
The Legacy API message lookup endpoints parsed the request body as JSON and
passed the `id` parameter straight through to the message database. A JSON
object supplied for `id` arrived as a Ruby Hash and was used as a raw set of
SQL `WHERE` conditions. `hash_to_sql` interpolated each Hash key directly
inside backtick identifier quoting while escaping only the value, so a key
containing a backtick could break out of the identifier and inject arbitrary
SQL into the SELECT (blind, time-based) against the message database.
Fixes:
- Escape all identifiers (columns, tables, database names) through a new
`escape_identifier` helper that wraps in backticks and doubles embedded
backticks. Applied across hash_to_sql, select, insert, insert_multi,
update and delete so no caller can inject via an identifier.
- Validate the Legacy API `id` parameter at the controller boundary: reject
any non-scalar value before it reaches the database and coerce it to an
integer. Internal Hash-based lookups (e.g. tracking middleware) are
unaffected.
Adds regression tests at the unit (hash_to_sql / escape_identifier) and
request (legacy messages/deliveries) levels.
url_with_return_to only checked that return_to started with a forward
slash, which also allowed protocol-relative values like //host and
/\host. Rails 7.1 already refuses to follow those via redirect_to, so
the user just saw a 500. Reject the same shapes in the helper instead
so we fall back to the default URL cleanly.
Adds a sessions request spec covering the rejected shapes plus the
happy-path relative redirect.
The endpoint and domain option helpers interpolated model attributes
straight into an HTML string before marking the whole buffer html_safe.
Wrap the interpolations in h() so untrusted attributes can't break out
of the surrounding tag.
Also stop the helpers glob in rails_helper from eagerly requiring
_spec.rb files so helper specs can live under spec/helpers/, and add a
small application helper spec covering the escape behaviour.
The /img/<server>/<message> endpoint accepted a src=<url> query
parameter and proxied the body of that URL back to the caller. Nothing
in the codebase ever produces a src= parameter — the parser only
inserts a plain tracking pixel and rewrites href links — so this branch
is dead code inherited from the original AppMail import.
Drop the src branch: requests with src now return 400. The no-src path
that serves the tracking pixel and records loads is unchanged, and a
spec covers both the pixel-serving path and the removed branch.
The app-wide CSP already blocks inline script execution, but the HTML
preview iframe for a stored email was same-origin and un-sandboxed, and
the html_raw response had no per-action hardening. Add a sandbox on the
iframe and tighten the CSP on html_raw to script-src 'none' with
nosniff and no-referrer so the preview has defence in depth against a
future CSP bypass or regression.
Relates to GHSA-f6g9-8555-cw28.
This will automatically increase the DB connection pool size if the number of threads needed in a worker is less than the maximum pool size configured.
This allows for these paths to continue to be set in the config file or environment variable while still maintaining the default of having the default paths in the same directory as the postal config file.
This commit also adds some of tests for the Domain model. It was during the writing of these tests that the DNS resolution refactoring requirement became apparent.
This adds a comprehensive set of tests for the message unqueueing service.
Additionally, it improves how message databases are used for testing environments.
