Replica: fix(message-parser): match parts on mime_type so multipart/related survives tracking#78
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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.
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 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.
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.
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…rfpg-3xr5) 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.
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 spec relied on the test machine having real IPv6 connectivity, which GitHub Actions runners do not have.
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…rvives tracking MessageParser#parse_parts matched on part.content_type, which is the full header value including parameters. A multipart/related container carrying the RFC 2387 type="text/html" parameter (emitted by PHPMailer and other senders for HTML mails with inline CID images) therefore matched the /text\/html/ branch first: the container's raw source was decoded and reassigned as a text body, and re-serialization rebuilt it as a broken multipart/alternative whose inline images no client renders. Matching on part.mime_type (bare MIME type, no parameters) routes such containers into the multipart branch, consistent with how generate() already inspects @mail.mime_type for non-multipart messages. Adds a regression spec covering the nested related container with a type parameter.
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Questa PR replica la PR originale: postalserver#3597
Autore originale: @cl77
Branch originale:
fix/message-parser-related-type-paramRepository originale: cl77/postal
Summary
MessageParser#parse_parts matches parts with case part.content_type, which returns the full Content-Type header value including parameters. A multipart/related container that carries the RFC 2387 type="text/html" parameter - which PHPMailer and other mainstream senders emit for HTML mails with inline CID images - therefore matches the first when /text/html/ branch instead of the multipart branch.
The consequences for any tracked message with that structure (multipart/alternative containing multipart/related with inline images):
Since the images then live in an alternative container rather than a related one, no mail client resolves the cid: references anymore - the message arrives without inline images, and the tracking pixel never reaches the real HTML part either. We hit this in production sending via the send/raw API with open tracking enabled.
Fix
Match on part.mime_type, the bare MIME type without parameters. This is consistent with generate(), which already inspects @mail.mime_type for non-multipart messages. No behavior change for any part whose Content-Type carries no parameters that collide with the matchers.
Repro / validation
Standalone reproduction with the mail gem (structure of the re-serialized message after parse_parts):
Before (case part.content_type):
multipart/alternative > [text/plain, multipart/alternative > [text/plain (raw container source), text/html, image/png]] - related container destroyed, Content-ID lost, no pixel in HTML.
After (case part.mime_type):
multipart/alternative > [text/plain, multipart/related > [text/html (pixel injected), image/png with Content-ID]] - structure intact.
A regression spec is included: it feeds a multipart/alternative message with a nested multipart/related; type="text/html" container through the parser with a track domain enabled and asserts the related container, its image part's Content-ID and the injected tracking pixel in the HTML leaf all survive.