Security audit follow-up. No Critical/High existed; these close the
Medium/Low findings.
F1 [Med] Host privilege boundary: a host could demote a peer host to
guest and then ban / PIN-reset (→ account takeover via /recover) them,
because the ban/pin-reset peer guards key off the target's *current*
role. set_role now blocks a non-admin from demoting a host.
F2 [Med] Moderation now revokes preview/thumbnail access: they are served
through visibility-checked aliases (/api/v1/upload/{id}/{preview,
thumbnail}) that filter soft-deleted / ban-hidden uploads, and direct
/media/previews|thumbnails is 404-blocked. Feed emits the gated URLs;
Caddy keeps them privately cacheable (max-age=300, short so moderation
revokes promptly — the live feed already evicts cards via SSE). Uses a
lean find_visible_media() (paths+mime only) on the media hot path.
F3 [Med/Low] npm audit fix: svelte 5.55.1→5.56.4 (SSR-XSS advisories),
devalue 5.6.4→5.8.1 (DoS). Prod deps: 0 vulnerabilities.
F4 [Low] /recover no longer leaks account existence: unknown display name
returns the same 401 as a wrong PIN, and runs a dummy bcrypt verify so
timing matches — closing the enumeration + timing oracle.
F5 [Low] SSE streams re-validate the session every ~60s and close once it
is logged out / expired, instead of running until client disconnect.
F6 [Info] X-Content-Type-Options: nosniff set at the app layer on all
media responses (defense-in-depth alongside the edge).
Tests: new e2e specs for F1 (host cannot demote peer host), F2 (preview
gated + 404 after delete + direct /media blocked), F4 (uniform 401).
40 backend unit tests + 182 e2e passing.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
H1: auth extractor re-reads the live user row — trusts the DB role (not the
JWT claim) and rejects banned users mid-session. e2e proves a demoted
host loses powers and a banned host is locked out and can't self-unban.
H2: client_ip takes the right-most XFF hop (the one Caddy appends); spoofed
left-most entries are ignored, restoring IP-based throttles.
H3: Caddy excludes /api/v1/stream from `encode` so SSE isn't buffered.
H4: upload — quota increment + row insert + hashtag links now one txn.
H5: feed keyset pagination tiebroken on (created_at, id) + composite index
(migration 010); feed_delta bounded with LIMIT.
H7: LightboxModal keys its comment load off upload.id, ending the
SSE-driven refetch storm.
H8: CSP via SvelteKit kit.csp (svelte.config.js) hardens the localStorage
token model against injection.
Migration 010 also adds the latent comment/comment_hashtag indexes.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Address the seven findings from the security & deployment review.
High:
- upload: make infer authoritative — reject files it can't identify
(SVG/HTML/JS) and require the detected MIME to be on an ALLOWED_MEDIA
allowlist; derive the stored MIME and on-disk extension from the
detected type, ignoring client filename/Content-Type. Closes the
stored-XSS vector via media served on-origin.
- deploy: rename docker-compose.override.yml -> docker-compose.dev.yml
so the default `docker compose up -d` no longer publishes Postgres
5432 to the host; the port map is now opt-in via -f. README updated.
Medium:
- upload: DefaultBodyLimit::disable() -> max(576 MiB) as an HTTP-level
OOM backstop; handler still enforces precise per-class size limits.
- docker: run backend and frontend as non-root users.
Low:
- social/upload: event-scope toggle_like, list_comments, add_comment,
delete_comment, edit_upload, delete_upload via find_by_id_and_event /
soft_delete_in_event — cross-event IDs now resolve to 404.
- Caddy: site-wide HSTS / nosniff / X-Frame-Options / Referrer-Policy,
plus Content-Disposition: attachment on /media/originals/*.
- .env.example: replace default Postgres password with a CHANGE_ME hint.
Out of scope: localStorage JWT (root cause fixed; httpOnly cookies are a
larger change tracked separately).
Verified: cargo build (no new warnings), cargo test (3 passed),
caddy validate, docker compose config (no 5432 published by default).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
