Security review of the DMARC report path (Fable, 2026-10-11), which ran
for the first time in 2.0.0. No Critical or High finding. Fixed:
- Medium: a report was bounded only as 8 MiB of XML - some 160 000
records or one name of megabytes, all of it rows and table cells. At
most 5 000 records (more is ErrRejected, dropped), text fields cut to
255 bytes on a character boundary, a record's count capped.
- Medium: the cap of 500 reports was for the whole server, so a stranger
filing under one domain's address evicted every other domain's
reports. PruneDMARCReports counts per domain.
- Low: the pipe service ran up to default_process_limit (100) commands
at once against the panel's database; maxproc is 1.
- Low: the reason logged for a dropped message carried the sender's
bytes (header line, zip entry name) as they came; cut to 200 bytes and
reduced to printable ASCII, zip entry names quoted.
- Low: SELFPOST_DATA_DIR / SELFPOST_DB_PATH with whitespace or "$" would
reach the command through export_environment as another path; refused
at start when DMARC ingest is on.
Left as they are, told to the owner: the parse-failure count is a
lifetime figure shown under "This week"; a report larger than the
command reads is dropped as unreadable; nested multipart is not searched.
The hub's Retention line follows the design commit before this one.
security.md: the review, and the accepted-risk entry says what a
stranger can and cannot do now. The roadmap no longer calls the review
pending.
go vet ./cmd/... ./internal/dmarc/ ./internal/store/: ok
go test ./cmd/... ./internal/dmarc/ ./internal/store/ ./internal/web/...: ok
make e2e on the test server (with the port-25 scenarios of the next
commit): ok
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Stage 3, step 2. Reviewed by Fable (read-only), fixed by Sonnet with a
failing test before each fix, checked by Opus. No Critical or High
finding: route authorization, tenant isolation by id, the /server/
subtree guard, output encoding and the origin check were found sound.
Fixed
- M1: a session was keyed by user name and had no link to the user. A
deleted or renamed user's cookie stayed alive (renewed on every hit,
before the user was looked up) and became a session of whoever was
later created under that name, with that account's role. The
baseline now has sessions.user_id REFERENCES users(id) ON DELETE
CASCADE; the principal is resolved by id and a session is renewed
only after its user was found. RenameSession is gone.
- M2: any user's password change deleted every other user's sessions.
It ends that user's other sessions only.
- L1: a password set on the user form ends that user's sessions (an
administrator editing their own account keeps the current one).
- L2: store, saslpasswd2 and Postfix reload errors were shown verbatim
on the application form, the inbound upstream / recipients forms and
the limit recalculation - pages a domain administrator reaches.
Validation errors (app.ValidationError, inbound.ValidationError,
store.ErrNotAutoRateLimit) keep their text; anything else is logged
and shown as "Could not save ... Check the logs and try again."
- L3: store.ListDMARCReports treated an empty domain list as "all". It
takes a scope now (AllDomains or a list; an empty list is no rows),
and the DMARC hub is open to the domain role as the plan says: the
reports of the assigned domains, without the instance-wide ingest
box. The menu entry was already shown to them and led to a 404.
- I1: /static/ answered with a listing of the embedded assets. A path
that is not a known asset is a 404.
Consequences
- The global DMARC hub lists reports of domains that were deleted
since, too.
- dev/migrate1x (not in the tree) no longer carries sessions over:
everyone signs in again after the transfer.
- docs/schema-migrations.md: the sessions row.
Recorded, not changed - for the owner:
- L4: the report-address select names the followed user and their
address to every administrator of the domain, by default the global
administrator's login name. The plan asks for it.
- L5: a delegated inbound upstream may be any host and port, loopback
and private ranges included - within the trusted-operator model; to
be listed among the accepted risks in security.md.
- L6: Account's profile is saved without the password; becomes a
requirement once password-reset mails to users.email.
- Still echoing an error's text: backup and domain import (global
only), the domain form's validation messages.
Not checked by the review: anything needing the container (e2e, real
Postfix / DNS), CSP behaviour in a live browser.
go test -count=1 ./internal/web/... ./internal/store/... ./internal/app/...
./internal/inbound/... ./internal/dmarc/... ./cmd/panel
ok (all eleven packages; dev/migrate1x also ok)
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Optional DMARC aggregate report ingest: accept `rua=` mail on port 25, parse gzip/XML into SQLite, and show summaries in the panel.
Added:
- Optional DMARC aggregate report ingest (`DMARC_REPORTS_ENABLE`): port 25
- Per-domain **SelfPost hosted** `rua=` mode when ingest is enabled
Full detail: CHANGELOG.md (1.7.0).