839a752341818d27989db599f618600f43ee4861
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Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
  mixandClaude Opus 5.5
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ecfe23504e |
antispam: rspamd 4.2.2-0, no capabilities, only the milter on the network (audit S4)
Security audit 2026-10-17, finding S4 (low), stage 4. The sidecar ran
rspamd 3.11.1 (December 2024) with default capabilities; upstream is 4.2.2
(2026-10-10), and the line between fixed a heap overflow in
util.lower_utf8, a use-after-free on reload and parser crashes - rspamd
reads every byte a stranger sends to port 25.
A read-only reading of rspamd 3.11.1 and 4.2.2 and of rspamd-docker
v3.11.1+3 and v4.2.2+0, side by side (sources in dev/upstream), found every
function SelfPost relies on unchanged: milter_headers (skip_wanted, the
custom routine, remove 0, create_specific_keyed, get_queue_id from {i}),
the X-Spamd-Result text, multimap (from/smtp, ip, the reject pre-result,
file-map rereading), the image's uid 11333 and CMD. It also found that the
image binds the normal worker (which takes client-named file and shm
inputs) and the controller (default password "q1") on every address,
reachable from any container on the compose network - so:
- image rspamd/rspamd:4.2.2-0 (the one build of 4.2.2; the others float);
- cap_drop: [ALL], no-new-privileges (rspamd starts unprivileged, ports
above 1024, nothing setuid);
- RSPAMD_LOCAL_ADDR=localhost keeps every worker on loopback, and a new
antispam/rspamd/worker-proxy.inc puts the proxy alone on *:11332. rspamd
expands its template syntax in comments too - the first version of that
comment quoted it and the config failed to load; it quotes none now.
Checked in a throwaway container on the test server with the three files
and the fragment's options (dev/server/rspamd-try.sh): proxy on any
address, 11333/11334 on loopback; from a private address a sender's own
verdict headers removed and rspamd's added; X-SelfPost-Filter equal to
openssl's HMAC-SHA256 of the queue id; a denied address refused with the
deny list's message; healthy. The e2e has no rspamd; the live sidecar is
checked at the rollout. Citations re-pointed to 4.2.2.
Docs: guide § Inbound relay (the third file; copy antispam/ again);
CHANGELOG; plan.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
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mixandClaude Opus 5.5
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1c6e04b7d3 |
base-trixie: the image on Debian trixie, Postfix 3.10.13; Received: hidden on 465/587
test / test (push) Canceled after 0s
The runtime base is debian:trixie-slim, the build stage golang:1.26-trixie:
Postfix 3.10.13 with upstream's 2026 security fixes up to the August
batch, libmilter 8.18.1, OpenSSL 3.5. Every citation of another program in
code, scripts and documents was re-read against the trixie sources
(dev/upstream; bookworm's kept in dev/upstream-bookworm) and updated;
development.md's cited-package table holds the trixie versions.
What the re-reading changed in behaviour:
- logtail: reject lines with sasl_method/sasl_username/sasl_sender
(smtpd_check.c:1019-1026); cleanup's "removed (canceled)" forgets a
port-25 id (cleanup_api.c:363-364).
- internal/postfix/retry.go reads postconf's stdout only: since 3.9 a
deprecated-parameter warning on stderr made one value too many and the
panel fell back to the compiled-in retry policy.
- logrotate-loop.sh: logrotate 3.22 exits 1 when it ignores a config;
the loop refuses on that output whatever the status.
- postfix-config.sh: cyrus_sasl_config_path set explicitly (bookworm's
07_sasl_config.diff is gone); maillog_file_permissions=0640; mynetworks
explicit; Dockerfile: SYNC_CHROOT= in /etc/default/postfix,
opendkim-tools dropped, openssl named, systemd-standalone-sysusers so
cron does not bring the whole of systemd.
- The selfpost group is 10998, outside the system range 100-999: in
trixie a package took 998 and the build failed (owner's decision:
a conflict-free id, the distribution's own ids untouched). The
entrypoint hands /data back by name when the user or the group differs.
Guide, backup refusal text, help (design commit
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mixandClaude Opus 5.5
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31c2b50457 |
antispam: rspamd strips a sender's own verdict for every client
test / test (push) Canceled after 0s
rspamd 3.11.1's milter_headers skips its verdict routines - removes none of the sender's X-Spamd-Result / X-Rspamd-Action, adds none - for a client it counts as local (loopback, a unix socket, local_addrs: the private ranges) or one that authenticated (skip_local, skip_authenticated, both on by default; milter_headers.lua skip_wanted(), lua_ip.c lua_ip_is_local()). The custom routine that signs X-SelfPost-Filter is never put through skip_wanted(), so it signed the sender's own verdict, and Inbound > Log showed it as rspamd's. Every sender is private when Docker's proxy relays port 25 from the bridge gateway. Both options set to false. Tried 2026-10-14 in a throwaway rspamd/rspamd:3.11.1-3 on the test server (rspamc --ucl, a message carrying its own verdict headers): old config, from 10.0.0.5 and as an authenticated user, the milter reply removed and added neither and added the signature; new config, both removed and rspamd's own added, as from 203.0.113.9. Also: the sender rules take the envelope only (extract_from = "smtp"; by default a bounce's From: header is used - tried: a bounce whose From: domain is denied was refused before, is not now; a denied sender is refused either way); the image pinned to 3.11.1-3, the build read (3.11 and 3.11.1 move with each rebuild); the prefilter lines no longer read go. architecture.md and security.md say so. Assumptions C-R7, B-R1, C-R4, C-R12, C-R5. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> |
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mixandClaude Opus 5.5
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599149bf83 |
build, deploy, inbound, dmarc, backup, e2e: cite the source of what they rely on (assumptions part C)
Comments only, no behaviour changed. Each main.cf/master.cf parameter the
build sets, the wrapper's and the reload hook's reliance on Postfix 3.7.11
(postfix-script, master.5, postconf.5, cleanup_init.c, smtpd_peer.c,
README_FILES), supervisor 4.2.5 (process.py, options.py, events.rst),
logrotate 3.21.0, OpenDKIM's config, Cyrus SASL's sasldb, rspamd 3.11.1
(milter_headers.lua, multimap, the map watcher), Docker Compose, CoreDNS
and certbot now say where that is written. Measurements already there stay
measurements ("date not recorded" where none was); hand-composed fixtures
say so.
Contradictions left for their own commits: C-P31 cleanup's size limit,
C-P42 master outside supervisor's signal, C-V5/V6 startsecs, C-V10,
C-S3/Q3 sasldb written in place, C-Q4/A1 certbot's symlinks, C-R7 rspamd
skips local clients but the signature routine does not, C-P8, C-R4, C-R12,
C-M7, C-E2, C-K8/K9, C-D1.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
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mixandClaude Opus 5.5
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1f44e40382 |
inbound-antispam-panel: the filter reads its signing key for every message
test / test (push) Canceled after 0s
The routine kept the key after its first read. SelfPost makes a new key when the file is lost or damaged, or a backup brings back another, and rspamd would then have gone on signing with the old one - every verdict unrecorded - until someone restarted the sidecar. The file is one short line; reading it per message costs nothing worth keeping a copy for. The guide says what never needs doing: nothing of rspamd's is cleared after a change of the lists or the key; a restart is for a change of its own configuration only. Prompted by the owner's question whether rspamd's cache needs clearing (2026-10-12). Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> |
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mixandClaude Opus 5.5
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d398f488e2 |
inbound-antispam-panel: the filter signs what it judged
test / test (push) Canceled after 0s
Closes what the security review left as an accepted risk: with the
spam filter down - it is attached fail-open - nothing removes verdict
headers a sender wrote himself, and the inbound journal recorded his
verdict as the filter's. The owner asked whether rspamd could add a
header that proves the others are ours (2026-10-12) and agreed to a
signature: a fixed mark could be written by a sender as easily as the
verdict.
- inbound.FilterKey: a key of 32 random bytes, 64 hex characters, in
/data/antispam/filter.key, made on the first start with the relay
on. 0644 like the list files beside it: the filter is another user
in another container.
- deploy/antispam/rspamd/milter_headers.conf: a custom routine reads
the key through the directory the sidecar already mounts and adds
X-SelfPost-Filter, the HMAC-SHA256 of the message's queue id, hex;
a header of that name from the sender is removed.
- internal/milter/inbound.go: the verdict headers are kept as they
are read, and at end-of-message - when the queue id is known - they
count only if the signature fits (FilterSignature, hmac.Equal). No
key, no queue id, no signature or a wrong one: the row is that of
mail nobody judged (accept, selfpost, no detail).
The signature goes on to the upstream with the mail and is of no use
there: it fits one queue id.
Tried in a throwaway rspamd 3.11 container on the test server before
the Go side was written: the routine loads, signs
(2aa1ca6d... for key 0123...cdef and queue id 4A1B2C3D5E, the value
python's hmac gives and TestFilterSignatureIsWhatTheFilterWrites
pins), removes a sender's header of the same name, and adds nothing
without a queue id.
Tests: signed, unsigned, made-up, another message's, another key's,
the sender's followed by the real one, the next message on the
connection, no queue id; the key made once, read after, replaced when
damaged, left alone by the lists. e2e: filter.key is there, 644, 65
bytes.
docs/security.md: the accepted risk is replaced by a narrower one (the
key is readable on the host); Mail path describes the signature.
Checked on the test server, uncommitted tree: go vet ./... ok,
go test ./... ok (22 packages), make e2e ok.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
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mixandClaude Opus 5.5
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28ec784ae2 |
inbound-antispam-panel: inbound journal milter on port 25
Step 3/12 of docs/plans/inbound-antispam-panel.md. The panel serves a second milter while the inbound relay is on (internal/milter/inbound.go, socket INBOUND_JOURNAL_MILTER_SOCKET, default /run/selfpost/inbound-journal.sock). build/postfix-config.sh puts it last on port 25, after the optional antispam milter, with default_action=accept; postfix-wrapper.sh waits for its socket. At end-of-message it writes one inbound_spam_log row per recipient at an inbound domain - other port-25 recipients (DMARC report addresses) get none - and always accepts. With a filter attached it reads the verdict from X-Rspamd-Action and X-Spamd-Result (action, score, up to six weighted symbols, only what the patterns recognise, 255 bytes); without one those headers are the sender's and are not read. The plan named X-Rspamd-Score, which rspamd does not have. The antispam compose fragment mounts rspamd/milter_headers.conf into the sidecar so that it adds the two headers (checked in rspamd 3.11: both routines exist and remove a sender's own headers of those names). Store: InsertInboundSpam, IsInboundDomain. Checked on the test server, uncommitted tree: go vet ./... ok, go test ./... ok (22 packages), make e2e ok - the relayed message of inbound_relay_delivers_and_refuses has its journal row (accept by selfpost) and the DMARC report sent through the same listener has none. Not yet seen in a real run: a verdict written by rspamd reaching this milter. The e2e stand has no filter, and the test server's only inbound domain has no upstream, so it accepts no mail. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> |