jensandClaude Sonnet 5
fd4d386108
Account has no hostname or key left to act on since the auth-binding fix, but its password predated the whole migration - rotated it via htpasswd -b. Verified new password works, old one is rejected, and the account is still fully inert for DNS updates either way. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
435 lines
28 KiB
Markdown
435 lines
28 KiB
Markdown
# alpha.jayfield.org — TODO
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Outstanding hardening items (see `README.md` for the full service overview).
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Nothing here is urgent; all are low-risk, no-downtime changes.
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- [ ] **Mail server IP (`89.58.8.149`) listed on Barracuda's BRBL** — found
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2026-07-25 (user report: "jayfield.org is on the Barracuda MX
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blacklist"). Confirmed via `dig +short 149.8.58.89.b.barracudacentral.org A`
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→ `127.0.0.2` (listed); clean on Spamhaus ZEN, SpamCop, and SORBS —
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Barracuda-specific. Checked the server for actual abuse before
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requesting removal: mail queue empty, outbound volume ~11 msgs over
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the prior week, only known SASL logins (`jens@`/`otto2022@jayfield.org`
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from the usual home IP), no backscatter, correct PTR
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(`alpha.jayfield.org`), SPF/DKIM/DMARC (`p=reject`) all already live —
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no sign of a compromised account or open relay, so most likely a
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stale/inherited reputation hit on the IP rather than active abuse
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from this host.
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Submitted a removal request via
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`https://www.barracudacentral.org/rbl/removal-request` on 2026-07-25.
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**Confirmation number: `BBR21785009436-19117-9182`.** Per Barracuda's
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response, the IP gets a temporary 48h reputation bump to "normal"
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while they investigate (up to ~1h to propagate), after which it
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either stays clear or reverts to listed.
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**Status 2026-07-26: still clear** (`dig +short
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149.8.58.89.b.barracudacentral.org A` → NXDOMAIN, no `127.0.0.2`) —
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matches the 1h check (routine `trig_01F1RMhEtNHtAbuHb9ffe1oX`, fired
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2026-07-25 21:02 UTC, also clear). This is expected during the 48h
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"normal" bump window, not yet proof of permanent delisting. The real
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test is the 48h check (routine `trig_019GayXSo5TW5eSxiJ99Ghrp`,
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scheduled 2026-07-27 20:03 UTC) — if it reverts to listed, next step
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is a manual follow-up to Barracuda citing the confirmation number
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above.
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- [x] **dyndns app has no real per-user auth binding** — found 2026-07-20,
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fixed 2026-07-26. `index.php`'s `pass == '_NO_PASS_'` check is a
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hardcoded magic string, not a real per-user credential — nothing tied
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the single shared Apache Basic Auth identity (`jens`, the only
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`.htpasswd` account) to *which* hostname label got updated. Confirmed
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live in the access log: a FritzBox ("Fritz!Box DDNS/1.0.3") was
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authenticating as `jens` while updating the `uschi` record — i.e. every
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device was already relying on this exact gap, self-policing which
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host it claimed via an unauthenticated `hostname=`/`user=` param.
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Fixed with real per-host TSIG binding, not just an app-level check:
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- Added a dedicated `.htpasswd` account for each of `kack`, `test`,
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`uschi`, `vpn` (`jens`'s existing account/password untouched).
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- Generated 5 per-host TSIG keys (`hmac-sha512`, `tsig-keygen`), one
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per hostname, each in its own `/etc/bind/<host>.dyndns.jayfield.org.key`
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(`root:bind 640` + `setfacl` grant for `www-data`, same pattern as
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the original key).
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- Replaced the zone's flat `allow-update { key dyndns.jayfield.org; };`
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in `named.conf.default-zones` with an `update-policy` granting each
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new key permission to update *only* its own name (`grant "<host>"
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name <host>. A AAAA TXT;`), plus one explicit legacy fallback grant
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for the original shared key (`subdomain` rule, zone-wide) — kept
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temporarily so unmigrated devices don't break (see below).
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- `nsupdate.php`/`nsupdate_ipv4.php`/`nsupdate_ipv6.php` now sign with
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the key belonging to `$_SERVER['PHP_AUTH_USER']` (the *authenticated*
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identity), not whatever hostname was requested. If they match, the
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new per-host key is used — BIND itself then refuses the update if
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that key isn't granted that name, independent of any PHP-side
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check. If the authenticated user is specifically the legacy `jens`
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account and doesn't match, it falls back to the old shared key
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(logged via `syslog(LOG_WARNING, ...)` for migration tracking) —
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every other account gets rejected outright (`-1`) on a mismatch,
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so newly-created per-host logins can never touch another host, even
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via the fallback.
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- Also fixed a pre-existing bug found in `nic/update.php` while
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testing this: it printed `good <ip>` unconditionally, without ever
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checking `nsupdate`'s return code — so a rejected update silently
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looked successful to the calling device. Now prints the real
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dyndns2-protocol response (`good <ip>` / `badauth`).
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All files backed up to
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`/root/removed-configs-backup/dyndns-per-host-auth-20260726094500/`.
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Validated with `named-checkconf`/`apache2ctl configtest`, applied via
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`rndc reload`/`systemctl reload apache2`. Tested both by driving
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`nsupdate()` directly as `www-data` and end-to-end over HTTPS with
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the new `vpn` credentials: own-host updates succeed, cross-host
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attempts from new accounts are rejected (`-1`/`badauth`) with the
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target record provably unchanged, and the legacy `jens`→`uschi`
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pattern still succeeds unchanged. Test IPs used during verification
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were restored to the real production values (`test`, `uschi`, `vpn`)
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immediately after; live `dig` confirmed the final state matches the
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pre-change records exactly.
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**Follow-up**: the `jens` legacy fallback (and its `.htpasswd`
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account) should stay only until every real device — including
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whichever ones are still authenticating as `jens` to update `uschi`
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— has been reconfigured with its own dedicated login. Once `dyndns
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legacy shared-key update` stops appearing in `syslog`, remove the
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fallback `grant` and the `jens` account can be scoped down to just
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its own host too.
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**`vpn` migrated 2026-07-26**: home FritzBox reconfigured with the
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new `vpn` login and confirmed live — after a WAN IP change (real
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connection recycle, not a test), the access log shows a genuine
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`Fritz!Box DDNS/1.0.3` request authenticated as `vpn` updating
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`vpn.dyndns.jayfield.org` to the new IP (`217.229.60.187`), and `dig`
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confirms the zone picked it up. First host fully off the legacy
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fallback. `uschi`'s device was reconfigured too but hasn't sent a
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real authenticated update yet (FritzBox only re-registers on WAN IP
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change or manual renew, neither has happened since) — not yet
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confirmed live.
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**`kack`/`test` removed 2026-07-26** instead of migrated: `kack`
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hadn't updated since Feb 2024 and `test` showed no real traffic in
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the (short) per-vhost access log history either — both looked like
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stale/unused entries rather than active devices, so removed outright
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rather than given dedicated logins. Deleted their `A`/`AAAA`/`TXT`
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records via `nsupdate` (using the legacy shared key), dropped their
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`update-policy` grants and `include` lines from
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`named.conf.default-zones`, moved their per-host TSIG key files and
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`.htpasswd` entries (`htpasswd -D`) out. Backed up to
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`/root/removed-configs-backup/dyndns-remove-kack-test-20260726101439/`.
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Validated with `named-checkconf`/`apache2ctl configtest`, applied via
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`rndc reload`/`systemctl reload apache2`, confirmed both names now
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resolve to nothing (`dig` empty) and `jens`/`uschi`/`vpn` untouched;
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`rndc sync` forced the on-disk zone file to reflect it immediately
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rather than waiting for BIND's next periodic dump.
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**`jens.dyndns.jayfield.org` hostname removed 2026-07-26** — same
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story as `kack`: stale since Feb 2024, no device actually updating
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it (the only `jens`-authenticated traffic ever seen was the legacy
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fallback updating *other* hosts, never its own). Deleted the record,
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dropped its dedicated `update-policy` grant and key `include` line,
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moved `jens.dyndns.jayfield.org.key` to
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`/root/removed-configs-backup/dyndns-remove-jenshost-20260726101844/`.
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Important distinction from the `kack`/`test` removal: this only
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removed the *hostname*. The `jens` **login** and the legacy shared-key
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fallback grant (`grant "dyndns.jayfield.org" subdomain
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dyndns.jayfield.org. ANY;`) were deliberately left in place, since
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`uschi`'s device still authenticates as `jens` through that fallback
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— removing the login would have broken it immediately. Re-verified
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after this change (direct `nsupdate()` call as `www-data`, writing
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`uschi`'s own current real IP back so nothing actually changed) that
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the `jens`→`uschi` legacy path still returns `0`. `named-checkconf`/
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`rndc reload` clean throughout.
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**Legacy fallback removed entirely 2026-07-26** — confirmed the
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`jens` fallback wasn't needed for `uschi` anymore (its own dedicated
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login/key from the original fix is what should be used going
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forward), and with `jens`'s and `kack`/`test`'s own hostnames already
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gone, nothing was left depending on it. Removed the
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`grant "dyndns.jayfield.org" subdomain dyndns.jayfield.org. ANY;`
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fallback grant and its key `include` from `named.conf.default-zones`;
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retired the original shared TSIG key itself
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(`/etc/bind/dyndns.jayfield.org.key`, in production since March 2022)
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to
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`/root/removed-configs-backup/dyndns-remove-legacy-fallback-20260726102228/`;
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removed the now-dead legacy-path branch from
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`nsupdate.php`/`nsupdate_ipv4.php`/`nsupdate_ipv6.php` — `nsupdate()`
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now unconditionally rejects (`-1`) any request where the
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authenticated user doesn't match the requested host, no exceptions.
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Verified: `jens` attempting to update `uschi` now fails immediately
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(`ret=-1`, no BIND round-trip at all — rejected in PHP before ever
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building an `nsupdate` command), while `uschi` and `vpn` updating
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themselves still succeed (`ret=0`, confirmed via `dig` against their
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real IPs). Per-user auth binding for dyndns is now unconditional,
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closing this item out completely — no more grandfathered exceptions
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of any kind. The `jens` `.htpasswd` account itself was left in place
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(not asked to remove it, and it's now inert for DNS updates anyway
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since it has no hostname or grant left to use).
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**`uschi` migration confirmed live 2026-07-26**: after the legacy
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fallback was removed, a real WAN IP change (connection recycle, not
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a test) produced a genuine `Fritz!Box DDNS/1.0.3` request
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authenticated as `uschi` updating `uschi.dyndns.jayfield.org` to
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`92.252.63.190`, confirmed via `dig`. (One wrinkle along the way: an
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earlier verification test of mine — writing `uschi`'s old IP back
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to confirm the fix — landed moments after that device's *first*
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post-migration update and clobbered it back to the stale value; the
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device's next natural IP change overwrote it correctly, so no
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lasting effect, but a reminder to use non-colliding test values when
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a real device might update concurrently.) Both `uschi` and `vpn` are
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now fully migrated to dedicated per-host logins with no legacy
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exceptions remaining anywhere in the setup.
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**`vpn` re-confirmed 2026-07-26**: a second WAN IP change produced
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another clean authenticated update (`87.180.9.214`), this time with
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no test collision — TXT timestamp matches exactly. Both `uschi` and
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`vpn` have now each been confirmed live across a real IP change with
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their own dedicated login; this item is fully done, nothing further
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to track.
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**`jens` password rotated 2026-07-26**: since the account is now
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unused (no hostname or key left to act on) and its old password
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predates this whole migration, rotated it for hygiene via
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`htpasswd -b`. Old `.htpasswd` backed up to
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`/root/removed-configs-backup/dyndns-jens-rotate-20260726124040/`.
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Verified: new password authenticates fine (`200`), old password now
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gets `401`, and — as expected since the fix — even a successful
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`jens` login still can't perform any DNS update (`badauth`). Account
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kept around (not asked to remove it), but fully inert either way.
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- [x] **dyndns/default-vhost access logging is a no-op** — done 2026-07-25
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found 2026-07-20 while investigating the command injection below.
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`dyndns.jayfield.org`, `jayfield.org`, `www.jayfield.org`,
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`mail.jayfield.org`, `web.jayfield.org`, and `cloud.jayfield.org`
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had no `CustomLog` directive of their own, and `access.log` (only
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written by `default-ssl.conf`/`000-default.conf`) had 0-8 lines —
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looking like no real vhost was being logged at all.
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Root cause (2026-07-25 re-check): the fallback assumption was wrong.
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There's no global `CustomLog access.log` in `apache2.conf`; instead
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`conf-enabled/other-vhosts-access-log.conf` enables `mod_vhost_combined`,
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which was already writing every vhost-without-its-own-`CustomLog`'s
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traffic to `/var/log/apache2/other_vhosts_access.log` (5,432 lines,
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confirmed real traffic incl. bot scans against `cloud.jayfield.org`).
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So requests were never actually un-logged — just commingled in one
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shared, harder-to-grep file instead of `access.log`.
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Fixed anyway, since a dedicated per-site log remains the better
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end state for incident review: added an explicit
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`CustomLog ${APACHE_LOG_DIR}/<site>_access.log combined` to every
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`<VirtualHost>` block for `dyndns`, `jayfield.org`, `www`, `mail`,
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`web`, `cloud`, and `portainer` (the `:80` and `:443`/`le-ssl` blocks
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of each site share one log file). Configs backed up to
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`/root/removed-configs-backup/vhost-customlog-20260725203959/`.
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`/etc/logrotate.d/apache2` already globs `*.log`, so no logrotate
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change needed. Validated with `apache2ctl configtest`, applied via
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`systemctl reload apache2`, verified live with `curl` against all 7
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domains and confirmed each new `<site>_access.log` recorded the hit.
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- [x] **OS command injection in the dyndns update scripts** — done 2026-07-20
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`/var/www/dyndns/nsupdate.php`, `nsupdate_ipv4.php`, and
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`nsupdate_ipv6.php` (used by both `index.php` and `nic/update.php`,
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the router/ddclient-facing endpoint) built a shell command string by
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directly interpolating unsanitized `$_GET` input (`hostname`/`myip`/
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`ip`, which become `$host`/`$ip`/`$ipv4`/`$ipv6`) and passed it to
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PHP's `exec()`, which runs it via `/bin/sh -c` — no
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`escapeshellarg()`/`escapeshellcmd()` anywhere. A request like
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`hostname=$(id>/tmp/pwned).dyndns.jayfield.org` would have executed
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arbitrary shell commands as `www-data` (the domain-suffix check
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still passed after the `.`-split). `nic/update.php` had no
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application-level auth of its own at all.
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Mitigating factor: the whole `dyndns.jayfield.org` vhost sits behind
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Apache Basic Auth, so this needed valid (or leaked/brute-forced)
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dyndns credentials to reach — not exploitable by an anonymous
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visitor. Compounding factors found during the audit: PHP is
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`7.4.33`, EOL since Nov 2022, `disable_functions` was empty (`exec`
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fully available); `index.php`'s `pass == '_NO_PASS_'` check is a
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hardcoded magic string, not real per-user auth, so any valid dyndns
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credential can update *any* of the zone's 5 hostnames (`jens`,
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`kack`, `test`, `uschi`, `vpn`), not just its own — left as-is, out
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of scope for this fix; and the vhost's access logging turned out to
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be a no-op (shared `access.log` has 0 lines), so past exploitation
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couldn't be fully ruled out from logs alone — though file mtimes,
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`www-data` processes/crontab, and zone contents all looked
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unremarkable, consistent with unexploited.
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Fixed: all three files backed up to
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`/root/removed-configs-backup/dyndns-preinjectionfix-<timestamp>/`,
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then rewritten to build the nsupdate command list as a plain string
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written to `proc_open()`'s stdin pipe using the **array form** of
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the command (`array("/usr/bin/nsupdate", "-k", ...)`) — this never
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invokes a shell at all, so no value can be interpreted as shell
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syntax regardless of content. Added strict `preg_match` validation
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requiring `$host`/`$domain` to be shaped like a valid hostname
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(letters/digits/hyphens, dot-separated labels) and
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`filter_var(..., FILTER_VALIDATE_IP, FILTER_FLAG_IPV4/IPV6)` on the
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IP before use, as defense in depth on top of removing the shell.
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**Regression found and fixed along the way**: functional testing
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showed legitimate updates were *already silently failing*
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(`update failed: REFUSED`, `permission denied` reading the TSIG
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key) — turned out `www-data` was never granted read access to
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`/etc/bind/dyndns.jayfield.org.key` when its permissions were
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tightened to `640 root:bind` in the item below, so the dyndns web
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update feature had been broken for real users since 2026-07-19,
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independent of this vulnerability. Fixed with a narrowly-scoped
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POSIX ACL (`setfacl -m u:www-data:r
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/etc/bind/dyndns.jayfield.org.key`, `acl` package installed) rather
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than adding `www-data` to the `bind` group — the group also owns
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`rndc.key` (full remote BIND control), which would have been a much
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bigger privilege grant than dyndns needs.
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Verified via `sudo -u www-data php` driving the real functions
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directly (same code path as the web UI, without needing the Basic
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Auth password): two injection payloads (`$(...)` and `;`-chained)
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both rejected (`-1`, no `/tmp` side-effect file created), an
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invalid IP rejected (`-1`), and a legitimate update succeeded
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(`0`), confirmed live in the zone via `dig`, then cleaned up (test
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record deleted via `nsupdate`, temp test script removed). Also
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confirmed unauthenticated requests still get `401` from Apache
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before ever reaching the PHP, and `apache2ctl configtest` stayed
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clean throughout.
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- [x] **Public static site (`jayfield.org`/`www.jayfield.org`) was 401'ing every visitor** — done 2026-07-20
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Found while auditing which services are reachable without credentials:
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a stray `/var/www/html/.htaccess` (`AuthType Basic`, same
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`AuthName "Restricted Content"`/`AuthUserFile /etc/apache2/.htpasswd`
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as the intentional `dyndns.jayfield.org` protection) was silently
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requiring login for the DocumentRoot both `jayfield.org` and
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`www.jayfield.org` share — `/var/www` has `AllowOverride all`, so it
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took effect with no vhost-level directive needed. File was dated
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2025-02-18 (`index.html`/`apache.html` themselves are from 2022) —
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predates every other change in this doc by well over a year, almost
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certainly a forgotten leftover rather than intentional, and
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contradicts `README.md`'s own description of both as a public static
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site.
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Fixed: moved to `/root/removed-configs-backup/htaccess-var-www-html.<timestamp>`
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(recoverable, not deleted — same convention as this file's other
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removed-config backups). No Apache reload needed (`.htaccess` is
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read per-request). Verified both `jayfield.org` and
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`www.jayfield.org` now return `200` with real page content;
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`dyndns.jayfield.org`'s own (intentional, vhost-level) Basic Auth is
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untouched and still returns `401` without credentials.
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- [x] **Lock down the dyndns TSIG key file permissions** — done 2026-07-19
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`/etc/bind/dyndns.jayfield.org.key` was `644` (world-readable), holding
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the shared secret that authenticates dynamic DNS updates for
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`dyndns.jayfield.org` with no IP-based `allow-update` backing it up.
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Fixed: `chmod 640` + `chown root:bind` (owner was already correct),
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matching `rndc.key`'s permissions.
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- [x] **Suppress BIND version disclosure** — done 2026-07-19
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No `version` statement in `named.conf.options`, so
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`dig CH TXT version.bind @ns1.jayfield.org` leaked the exact BIND
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version (`9.18.39`) — a minor fingerprinting aid for attackers.
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Fixed: added `version "unknown";` inside the `options {}` block,
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validated with `named-checkconf`, and applied via `rndc reload`.
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Verified `dig CH TXT version.bind` now returns `"unknown"`.
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- [x] **Add response rate limiting (RRL)** — done 2026-07-19
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No `rate-limit {}` block was configured. Since `allow-query { any; }`
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is required for a public authoritative zone, RRL is the standard
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mitigation against the server being used for spoofed-source DNS
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reflection/amplification against third parties.
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Fixed: added `rate-limit { responses-per-second 10; window 5; }` to
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`named.conf.options`, validated with `named-checkconf`, and applied
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via `rndc reload`. Started with conservative defaults (10/s, 5s
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window) — revisit if legitimate high-volume resolvers get throttled.
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- [x] **Add HSTS headers to all vhosts** — done 2026-07-19
|
|
No vhost sent a `Strict-Transport-Security` header, leaving a window
|
|
for on-path SSL-stripping on a user's very first plaintext request to
|
|
any domain.
|
|
Fixed: added `Header always set Strict-Transport-Security
|
|
"max-age=63072000; includeSubDomains"` to all 6 domain `:443` blocks
|
|
(`dyndns`, `jayfield.org`, `www`, `mail`, `web`, `cloud`) — skipped
|
|
`default-ssl.conf` since it's the self-signed catch-all with no real
|
|
trusted hostname for a browser to pin. Validated with
|
|
`apache2ctl configtest`, applied via `systemctl reload apache2`,
|
|
verified live with `curl -sI` against all 6 domains.
|
|
|
|
- [x] **`jayfield.org` had no `:80` vhost of its own** — done 2026-07-19
|
|
Bare `http://jayfield.org` fell through to the `dyndns` default vhost
|
|
and redirected to the wrong domain.
|
|
Fixed: added a `:80` block to `jayfield.org.conf` redirecting to
|
|
`https://jayfield.org/`, matching the `dyndns`/`mail` pattern.
|
|
Verified: `curl -sI http://jayfield.org/` → `302` with
|
|
`Location: https://jayfield.org/`.
|
|
|
|
- [x] **SSH: disable root login + password auth** — done 2026-07-19
|
|
`PermitRootLogin yes` and `PasswordAuthentication yes` were both still
|
|
enabled (the "known deviation" flagged in `SETUP.md` §1) — every
|
|
credential-stuffing bot on the internet got a real login prompt to
|
|
grind against.
|
|
Fixed: `PermitRootLogin no`, `PasswordAuthentication no`,
|
|
`PubkeyAuthentication yes` in `/etc/ssh/sshd_config` (backed up as
|
|
`sshd_config.bak.20260719225249`). The `Match Group sftp` block's own
|
|
`PasswordAuthentication yes` was left as-is — separate, already-chrooted,
|
|
no-shell/no-forwarding accounts, not part of this risk. Validated with
|
|
`sshd -t`, applied via `systemctl reload sshd`, verified live with
|
|
`sshd -T` and a fresh key-only connection before considering it done.
|
|
|
|
- [x] **Portainer's `:9443` UI is unreachable in HSTS-enforcing browsers** — done 2026-07-20
|
|
`https://alpha.jayfield.org:9443` threw
|
|
`MOZILLA_PKIX_ERROR_SELF_SIGNED_CERT` in Firefox with no click-through
|
|
option ("keine Ausnahme kann hinzugefügt werden"). Root cause: the
|
|
`includeSubDomains` HSTS policy sent by the real `alpha.jayfield.org`
|
|
vhost (`Strict-Transport-Security` header, added in the item above)
|
|
pins the *hostname* to HTTPS-with-a-trusted-cert on every port, but
|
|
Portainer (`README.md` §Docker services) was still serving its stock
|
|
self-signed cert directly on `9443`. Not a MITM — self-inflicted by
|
|
combining HSTS with an unproxied self-signed service.
|
|
Fixed: added a `portainer` A record to `db.jayfield.org` (SOA serial
|
|
`2022032216` → `2022032217`); recreated the `portainer` container
|
|
binding the HTTPS UI to `127.0.0.1:9443:9443` instead of publishing it
|
|
(old container kept renamed until the new one was verified, then
|
|
removed, matching the update procedure documented in `README.md`);
|
|
added an Apache vhost for `portainer.jayfield.org`
|
|
(`ProxyPass`/`ProxyPassReverse` to `https://127.0.0.1:9443/`,
|
|
`SSLProxyEngine on`, `SSLProxyVerify none` + `SSLProxyCheckPeerCN off`/
|
|
`SSLProxyCheckPeerName off` for the loopback hop to Portainer's
|
|
self-signed cert) — same pattern as `web.jayfield.org`/
|
|
`cloud.jayfield.org` (`SETUP.md` §4/§5); issued a real cert via
|
|
`certbot --apache -d portainer.jayfield.org --redirect`; added the
|
|
standard HSTS header. Left the `8000` edge-agent tunnel port
|
|
published as-is — no evidence it's in use.
|
|
Verified: `openssl s_client`/`curl` confirm the Let's Encrypt cert
|
|
(not self-signed) and `Strict-Transport-Security` header on
|
|
`https://portainer.jayfield.org`, `http://` redirects 301 to
|
|
`https://`, and `ss -ltnp` shows `9443` bound to `127.0.0.1` only
|
|
(via `docker-proxy`), so it's no longer reachable on the public
|
|
interface at all — access is now exclusively via
|
|
`https://portainer.jayfield.org`.
|
|
One transient wrinkle during rollout: the very first few requests
|
|
through the new proxy vhost returned a stray `401` with dyndns's
|
|
Basic Auth realm ("Restricted Content") — looked alarming, but
|
|
`LogLevel trace8` on the vhost showed Apache correctly SNI-matching
|
|
and proxying to the new container with a clean backend `200`;
|
|
resolved itself within seconds (looked like a stale pooled proxy
|
|
connection surviving the container recreate) and was stable across
|
|
repeated checks before the debug logging was removed again.
|
|
|
|
- [x] **fail2ban: `sshd` jail was evadable via low-and-slow attempts** — done 2026-07-19
|
|
Default `findtime=30m`/`maxretry=3` never triggered for `47.76.192.176`,
|
|
which had been hitting `root`/`jayfield` logins roughly every 33 minutes
|
|
for most of a day — just outside the 30-minute window, so failures kept
|
|
aging out before reaching 3 strikes. Confirmed via `fail2ban.log`
|
|
(`Found`/`Ban` counts) that no other jail showed the same per-IP timing
|
|
pattern; a separate, *distributed* single-shot scan on `apache-noscript`
|
|
was noted but left open (see `README.md`).
|
|
Fixed: `/etc/fail2ban/jail.d/sshd-findtime.local` overrides `sshd` to
|
|
`findtime=1d`, `maxretry=4`, `bantime=1d`, kept in its own drop-in
|
|
rather than editing the Debian-packaged jail file. Applied via
|
|
`fail2ban-client reload sshd`; `47.76.192.176` was banned on its very
|
|
next attempt after the change.
|
|
|
|
- [x] **fail2ban: `dovecot` jail had the same low-and-slow gap as `sshd`** — done 2026-07-25
|
|
found while auditing which IPs were hitting webmail hard enough to
|
|
deserve a ban but weren't in any currently-banned list. Same default
|
|
`findtime=30m`/`maxretry=3` as `sshd`'s pre-fix config. At least 4 IPs
|
|
(`47.95.196.60` 167 hits, `82.157.132.42` 144, `120.48.118.132` 76,
|
|
`188.164.195.116` 57, `157.245.38.26` 34) ran a coordinated IMAP
|
|
password spray against generic mailbox names (`admin@`, `test@`,
|
|
`support@`, `sales@jayfield.org`) starting almost simultaneously around
|
|
2026-07-21 22:40-23:38, each pacing itself at ~1 attempt/22-25min —
|
|
just outside the 30-minute window, so none ever tripped 3 strikes.
|
|
`120.48.118.132` was still active as late as 2026-07-25 13:32, so the
|
|
campaign was ongoing, not historical. `postfix-sasl` shares the same
|
|
default thresholds and mail stack but showed much lower per-IP volume
|
|
in this pass — worth a follow-up check if it starts trending the same
|
|
way.
|
|
**Follow-up 2026-07-26**: checked `postfix-sasl` — still just scattered
|
|
background noise, not a coordinated campaign. Top offender
|
|
(`172.94.9.203`) logged 32 hits but all from late June/early July, none
|
|
since; current activity is single/double attempts from many different
|
|
IPs (no repeated per-IP low-and-slow pattern like the dovecot spray).
|
|
`findtime=30m`/`maxretry=3` defaults left as-is — no fix needed unless
|
|
this changes.
|
|
Fixed: `/etc/fail2ban/jail.d/dovecot-findtime.local`, same values as
|
|
the `sshd` fix (`findtime=1d`, `maxretry=4`, `bantime=1d`). Applied via
|
|
`fail2ban-client reload dovecot`; verified live with
|
|
`fail2ban-client get dovecot findtime/maxretry/bantime` and confirmed
|
|
the jail's existing ban state (`47.88.56.201`, 29 total bans) survived
|
|
the reload.
|