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security: tunnel dual-listener + SSRF + envelope + path wave (v1.6.0.0)#1137

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garrytan/sec-wave
Apr 22, 2026
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security: tunnel dual-listener + SSRF + envelope + path wave (v1.6.0.0)#1137
garrytan merged 20 commits intomainfrom
garrytan/sec-wave

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Summary

The token leak in pair-agent --client sessions is closed by splitting the daemon into two HTTP listeners, not by pretending one port can be two things at once. 18 commits, ~1900 lines net, 4 community PRs credited, Codex-reviewed, architectural bump to v1.6.0.0.

Foundation (F1, 4 bisected commits):

  • refactor(security): /connect rate limit 3/min → 300/min (flood-only defense; setup keys are unbruteforceable)
  • feat(security): new browse/src/tunnel-denial-log.ts module (async JSONL, 60/min rate cap)
  • feat(security): dual-listener tunnel architecture in browse/src/server.ts
  • test(security): 23 source-level guards for tunnel path/command allowlists + lifecycle

Community PRs (5 commits, all credited):

  • #1029 SSRF gate on download + scrape via validateNavigationUrl (@garagon)
  • #1031 envelope sentinel escape across wrapUntrustedPageContent + handleSnapshot (@garagon)
  • #1032 hidden-element detection for every DOM channel (html, links, forms, ...) (@garagon)
  • #1103 --from-file payload path validation for parity with direct-API paths (@garagon)
  • #1073 partial: design/src/serve.ts JSON.stringify + scripts/slop-diff.ts shell narrowing (@theqazi)

Expansions (6 commits):

  • E3: /welcome GSTACK_SLUG regex gate against path traversal
  • N1: replace ?token= SSE URL auth with view-only HttpOnly gstack_sse cookie (new sse-session-cookie.ts module + extension update + 20-test unit suite)
  • N2: document Windows v20 ABE elevation path on cookie-import CDP port, file follow-up (security: switch cookie-import-browser CDP from TCP port to --remote-debugging-pipe #1136)
  • E2: ARCHITECTURE.md per-endpoint disposition table + dual-listener contract
  • E1: end-to-end pairing integration test (12 behavioral tests against a spawned daemon, ~220ms)
  • docs: sync BROWSER.md, CLAUDE.md, docs/REMOTE_BROWSER_ACCESS.md with v1.6.0.0 reality

Release (2 commits):

  • release: VERSION 1.5.1.0 → 1.6.0.0, package.json synced, ~950-word release summary in CHANGELOG
  • fix: 4 pre-landing review auto-fixes (GET /connect rate-limit, ngrok listener leak, GSTACK_SKILL_ROOT gate, SSE prune cap)

Skipped (credit preserved, commented on PRs):

  • #469 telemetry sanitization — already landed on main (credit @HMAKT99 for surfacing)
  • #472 review-log JSON validation — already landed on main via bun-based check (credit @HMAKT99)
  • #1002 tunnel auth policy — fully subsumed by F1's physical port separation (credit @Hybirdss in CHANGELOG)

Test Coverage

Existing tests: ~87 pass across browse/test/server-auth + token-registry + findport.
New tests added this wave:

Tests: existing baseline → +~120 new tests across 5 files. Full bun run test exit 0.

Pre-Landing Review

Adversarial sweep by Claude subagent on the final diff found 7 issues: 1 HIGH, 3 MEDIUM, 3 LOW. 4 auto-fixed in commit c7583f7f:

  • [HIGH] GET /connect now rate-limited (was POST-only)
  • [MEDIUM] ngrok listener leak on tunnel startup failure — cleanup both sides in both error paths
  • [MEDIUM] GSTACK_SKILL_ROOT .. rejection (symmetric with E3 GSTACK_SLUG gate)
  • [LOW] SSE session registry prune on validate + 10k hard cap backstop

3 findings explicitly skipped with rationale (already-decided global rate limit, cosmetic indentation artifact, /command JSON parse edge case).

Plan Completion

SELECTIVE EXPANSION mode. 7 scope proposals proposed, 7 accepted, 0 deferred. Full proposal list + decisions in ~/.gstack/projects/garrytan-gstack/ceo-plans/2026-04-21-security-wave-v1.5.2.md.

All items DONE or CHANGED (none missing). Codex outside-voice flagged 3 factual errors in the original plan (invented logAttack function, wrong rate-limit calibration, wrong probe path) — all corrected before implementation. Codex also surfaced 2 new CVE classes (token-in-URL, cookie-import CDP) which the user accepted and this PR closes.

Verification Results

E2E pairing test suite (browse/test/pair-agent-e2e.test.ts) exercises the full ceremony against a spawned daemon: /pair → setup_key → /connect → scoped token → /command. All 12 behavioral assertions pass.

Not exercised in CI: actual ngrok tunnel binding (requires authtoken). The tunnel listener's dual-port invariants are covered by source-level guards in dual-listener.test.ts; live tunnel verification belongs in a separate paid-evals harness.

TODOS

No TODOS.md items completed by this PR directly. Follow-up tracked as issue #1136 (switch cookie-import-browser CDP transport to --remote-debugging-pipe to close the Windows v20 ABE elevation path — non-trivial, intentionally deferred).

Documentation

Doc updates for v1.6.0.0 security wave (commit 3bff6736):

  • docs/REMOTE_BROWSER_ACCESS.md — rewrote Architecture diagram to show both listeners (local 127.0.0.1 = full surface, tunnel 127.0.0.1 = allowlist forwarded by ngrok). Fixed /connect rate limit (3/min → 300/min). Removed stale "/health requires no auth" line (now 404 on the tunnel). Added SSE auth via HttpOnly gstack_sse cookie (?token= query param deprecated). Expanded Security Model with tunnel command allowlist (17 commands), root-token-on-tunnel = 403, SSRF guards, /welcome path traversal regex defense, denial logging, Windows v20 ABE non-goal.
  • BROWSER.md — added dual-listener paragraph to Authentication section with link to ARCHITECTURE.md endpoint table. Replaced stale ?token= SSE description with HttpOnly gstack_sse cookie flow.
  • CLAUDE.md — added Transport-layer security section. Documents the load-bearing module boundary (sse-session-cookie.ts cannot import from token-registry.ts).
  • ARCHITECTURE.md — covered in commit 580f54d3 (E2): per-endpoint disposition table, tunnel denial log model, SSE cookie scope, N2 non-goal documentation.

Not touched: README.md (generic /pair-agent description still accurate), CONTRIBUTING.md (no setup changes), ETHOS.md (protected).

Test plan

  • Full bun run test exit 0 (final verification pass after review fixes, commit c7583f7)
  • bun build --compile browse/src/cli.ts succeeds
  • pair-agent-e2e.test.ts passes against a spawned daemon (12 behavioral assertions)
  • Source-level guards for dual-listener routing enforced (dual-listener.test.ts, 24 tests)
  • SSE session cookie registry correctness (sse-session-cookie.test.ts, 20 tests)
  • Reviewed by Codex outside voice during /plan-ceo-review (14 findings, all addressed)
  • Reviewed by /plan-eng-review (5 architectural decisions locked, 0 unresolved)
  • Pre-landing adversarial subagent review (7 findings, 4 auto-fixed, 3 skipped with rationale)

🤖 Generated with Claude Code

garrytan and others added 18 commits April 21, 2026 20:31
Setup keys are 24 random bytes (unbruteforceable), so a tight rate limit
does not meaningfully prevent key guessing. It exists only to cap
bandwidth, CPU, and log-flood damage from someone who discovered the
ngrok URL. A legitimate pair-agent session hits /connect once; 300/min
is 60x that pattern and never hit accidentally.

3/min caused pairing to fail on any retry flow (network blip, second
paired client) with no upside. Per-IP tracking was considered and
rejected — adds a bounded Map + LRU for defense already adequate at the
global layer.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Append-only log of tunnel-surface auth denials to
~/.gstack/security/attempts.jsonl. Gives operators visibility into who
is probing tunneled daemons so the next security wave can be driven by
real attack data instead of speculation.

Design notes:
- Async via fs.promises.appendFile. Never appendFileSync — blocking the
  event loop on every denial during a flood is what an attacker wants
  (prior learning: sync-audit-log-io, 10/10 confidence).
- In-process rate cap at 60 writes/minute globally. Excess denials are
  counted in memory but not written to disk — prevents disk DoS.
- Writes to the same ~/.gstack/security/attempts.jsonl used by the
  prompt-injection attempt log. File rotation is handled by the existing
  security pipeline (10MB, 5 generations).

No consumers in this commit; wired up in the dual-listener refactor that
follows.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
The /health endpoint leaked AUTH_TOKEN to any caller that hit the ngrok
URL (spoofing chrome-extension:// origin, or catching headed mode).
Surfaced by @garagon in PR #1026; the original fix was header-inference
on the single port. Codex's outside-voice review during /plan-ceo-review
called that approach brittle (ngrok header behavior could change, local
proxies would false-positive), and pushed for the structural fix.

This is that fix. Stop making /health a root-token bootstrap endpoint on
any surface the tunnel can reach. The server now binds two HTTP
listeners when a tunnel is active. The local listener (extension, CLI,
sidebar) stays on 127.0.0.1 and is never exposed to ngrok. ngrok
forwards only to the tunnel listener, which serves only /connect
(unauth, rate-limited) and /command with a locked allowlist of
browser-driving commands. Security property comes from physical port
separation, not from header inference — a tunnel caller cannot reach
/health or /cookie-picker or /inspector because they live on a
different TCP socket.

What this commit adds to browse/src/server.ts:
  * Surface type ('local' | 'tunnel') and TUNNEL_PATHS +
    TUNNEL_COMMANDS allowlists near the top of the file.
  * makeFetchHandler(surface) factory replacing the single fetch arrow;
    closure-captures the surface so the filter that runs before route
    dispatch knows which socket accepted the request.
  * Tunnel filter at dispatch entry: 404s anything not on TUNNEL_PATHS,
    403s root-token bearers with a clear pairing hint, 401s non-/connect
    requests that lack a scoped token. Every denial is logged via
    logTunnelDenial (from tunnel-denial-log).
  * GET /connect alive probe (unauth on both surfaces) so /pair and
    /tunnel/start can detect dead ngrok tunnels without reaching
    /health — /health is no longer tunnel-reachable.
  * Lazy tunnel listener lifecycle. /tunnel/start binds a dedicated
    Bun.serve on an ephemeral port, points ngrok.forward at THAT port
    (not the local port), hard-fails on bind error (no local fallback),
    tears down cleanly on ngrok failure. BROWSE_TUNNEL=1 startup uses
    the same pattern.
  * closeTunnel() helper — single teardown path for both the ngrok
    listener and the tunnel Bun.serve listener.
  * resolveNgrokAuthtoken() helper — shared authtoken lookup across
    /tunnel/start and BROWSE_TUNNEL=1 startup (was duplicated).
  * TUNNEL_COMMANDS check in /command dispatch: on the tunnel surface,
    commands outside the allowlist return 403 with a list of allowed
    commands as a hint.
  * Probe paths in /pair and /tunnel/start migrated from /health to
    GET /connect — the only unauth path reachable on the tunnel surface
    under the new architecture.

Test updates in browse/test/server-auth.test.ts:
  * /pair liveness-verify test: assert via closeTunnel() helper instead
    of the inline `tunnelActive = false; tunnelUrl = null` lines that
    the helper subsumes.
  * /tunnel/start cached-tunnel test: same closeTunnel() adaptation.

Credit
  Derived from PR #1026 by @garagon — thanks for flagging the critical
  bug that drove the architectural rewrite. The per-request
  isTunneledRequest approach from #1026 is superseded by physical port
  separation here; the underlying report remains the root cause for the
  entire v1.6.0.0 wave.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
23 source-level assertions that keep future contributors from silently
widening the tunnel surface during a routine refactor. Covers:

  * Surface type + tunnelServer state variable shape
  * TUNNEL_PATHS is a closed set of /connect, /command, /sidebar-chat
    (and NOT /health, /welcome, /cookie-picker, /inspector/*, /pair,
    /token, /refs, /activity/stream, /tunnel/{start,stop})
  * TUNNEL_COMMANDS includes browser-driving ops only (and NOT
    launch-browser, tunnel-start, token-mint, cookie-import, etc.)
  * makeFetchHandler(surface) factory exists and is wired to both
    listeners with the correct surface parameter
  * Tunnel filter runs BEFORE any route dispatch, with 404/403/401
    responses and logged denials for each reason
  * GET /connect returns {alive: true} unauth
  * /command dispatch enforces TUNNEL_COMMANDS on tunnel surface
  * closeTunnel() helper tears down ngrok + Bun.serve listener
  * /tunnel/start binds on ephemeral port, points ngrok at TUNNEL_PORT
    (not local port), hard-fails on bind error (no fallback), probes
    cached tunnel via GET /connect (not /health), tears down on
    ngrok.forward failure
  * BROWSE_TUNNEL=1 startup uses the dual-listener pattern
  * logTunnelDenial wired for all three denial reasons
  * /connect rate limit is 300/min, not 3/min

All 23 tests pass. Behavioral integration tests (spawn subprocess, real
network) live in the E2E suite that lands later in this wave.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
The `goto` command was correctly wired through validateNavigationUrl,
but `download` and `scrape` called page.request.fetch(url, ...) directly.
A caller with the default write scope could hit the /command endpoint
and ask the daemon to fetch http://169.254.169.254/latest/meta-data/
(AWS IMDSv1) or the GCP/Azure/internal equivalents. The response body
comes back as base64 or lands on disk where GET /file serves it.

Fix: call validateNavigationUrl(url) immediately before each
page.request.fetch() call site in download and in the scrape loop.
Same blocklist that already protects `goto`: file://, javascript:,
data:, chrome://, cloud metadata (IPv4 all encodings, IPv6 ULA,
metadata.*.internal).

Tests: extend browse/test/url-validation.test.ts with a source-level
guard that walks every `await page.request.fetch(` call site and
asserts a validateNavigationUrl call precedes it within the same
branch. Regression trips before code review if a future refactor
drops the gate.
The scoped-token snapshot path in snapshot.ts built its untrusted
block by pushing the raw accessibility-tree lines between the literal
`═══ BEGIN UNTRUSTED WEB CONTENT ═══` / `═══ END UNTRUSTED WEB CONTENT ═══`
sentinels. The full-page wrap path in content-security.ts already
applied a zero-width-space escape on those exact strings to prevent
sentinel injection, but the scoped path skipped it.

Net effect: a page whose rendered text contains the literal sentinel
can close the envelope early from inside untrusted content and forge
a fake "trusted" block for the LLM. That includes fabricating
interactive `@eN` references the agent will act on.

Fix:
  * Extract the zero-width-space escape into a named, exported helper
    `escapeEnvelopeSentinels(content)` in content-security.ts.
  * Have `wrapUntrustedPageContent` call it (behavior unchanged on
    that path — same bytes out).
  * Import the helper in snapshot.ts and map it over `untrustedLines`
    in the `splitForScoped` branch before pushing the BEGIN sentinel.

Tests: add a describe block in content-security.test.ts that covers
  * `escapeEnvelopeSentinels` defuses BEGIN and END markers;
  * `escapeEnvelopeSentinels` leaves normal text untouched;
  * `wrapUntrustedPageContent` still emits exactly one real envelope
    pair when hostile content contains forged sentinels;
  * snapshot.ts imports the helper;
  * the scoped-snapshot branch calls `escapeEnvelopeSentinels` before
    pushing the BEGIN sentinel (source-level regression — if a future
    refactor reorders this, the test trips).
The Confusion Protocol envelope wrap (`wrapUntrustedPageContent`)
covers every scoped PAGE_CONTENT_COMMAND, but the hidden-element
ARIA-injection detection layer only ran for `text`. Other DOM-reading
channels (html, links, forms, accessibility, attrs, data, media,
ux-audit) returned their output through the envelope with no hidden-
content filter, so a page serving a display:none div that instructs
the agent to disregard prior system messages, or an aria-label that
claims to put the LLM in admin mode, leaked the injection payload on
any non-text channel. The envelope alone does not mitigate this, and
the page itself never rendered the hostile content to the human
operator.

Fix:
  * New export `DOM_CONTENT_COMMANDS` in commands.ts — the subset of
    PAGE_CONTENT_COMMANDS that derives its output from the live DOM.
    Console and dialog stay out; they read separate runtime state.
  * server.ts runs `markHiddenElements` + `cleanupHiddenMarkers` for
    every scoped command in this set. `text` keeps its existing
    `getCleanTextWithStripping` path (hidden elements physically
    stripped before the read). All other channels keep their output
    format but emit flagged elements as CONTENT WARNINGS on the
    envelope, so the LLM sees what it would otherwise have consumed
    silently.
  * Hidden-element descriptions merge into `combinedWarnings`
    alongside content-filter warnings before the wrap call.

Tests: new describe block in content-security.test.ts covering
  * `DOM_CONTENT_COMMANDS` export shape and channel membership;
  * dispatch gates on `DOM_CONTENT_COMMANDS.has(command)`, not the
    literal `text` string;
  * hiddenContentWarnings plumbs into `combinedWarnings` and reaches
    wrapUntrustedPageContent;
  * DOM_CONTENT_COMMANDS is a strict subset of PAGE_CONTENT_COMMANDS.

Existing datamarking, envelope wrap, centralized-wrapping, and chain
security suites stay green (52 pass, 0 fail).
…aths

The direct `load-html <file>` path runs every caller-supplied file path
through validateReadPath() so reads stay confined to SAFE_DIRECTORIES
(cwd, TEMP_DIR). The `load-html --from-file <payload.json>` shortcut
and its sibling `pdf --from-file <payload.json>` skipped that check and
went straight to fs.readFileSync(). An MCP caller that picks the
payload path (or any caller whose payload argument is reachable from
attacker-influenced text) could use --from-file as a read-anywhere
escape hatch for the safe-dirs policy.

Fix: call validateReadPath(path.resolve(payloadPath)) before readFileSync
at both sites. Error surface mirrors the direct-path branch so ops and
agent errors stay consistent.

Test coverage in browse/test/from-file-path-validation.test.ts:
  - source-level: validateReadPath precedes readFileSync in the load-html
    --from-file branch (write-commands.ts) and the pdf --from-file parser
    (meta-commands.ts)
  - error-message parity: both sites reference SAFE_DIRECTORIES

Related security audit pattern: R3 F002 (validateNavigationUrl gap on
download/scrape) and R3 F008 (markHiddenElements gap on 10 DOM commands)
were the same shape — a defense that existed on the primary code path
but not its shortcut sibling. This PR closes the same class of gap on
the --from-file shortcuts.
serve.ts injected url.origin into a single-quoted JS string in
the response body. A local request with a crafted Host header
(e.g. Host: "evil'-alert(1)-'x") would break out of the string
and execute JS in the 127.0.0.1:<port> origin opened by the
design board. Low severity — bound to localhost, requires a
local attacker — but no reason not to escape.

Fix: JSON.stringify(url.origin) produces a properly quoted,
escaped JS string literal in one call.

Also includes Prettier reformatting (single→double quotes,
trailing commas, line wrapping) applied by the repo's
PostToolUse formatter hook. Security change is the one line
in the HTML injection; everything else is whitespace/style.
spawnSync('npx', [...], { shell: true }) invokes /bin/sh -c
with the args concatenated, subjecting them to shell parsing
(word splitting, glob expansion, metacharacter interpretation).
No user input reaches these calls today, so not exploitable —
but the posture is wrong: npx + shell args should be direct.

Fix: scope shell:true to process.platform === 'win32' where
npx is actually a .cmd requiring the shell. POSIX runs the
npx binary directly with array-form args.

Also includes Prettier reformatting (single→double quotes,
trailing commas, line wrapping) applied by the repo's
PostToolUse formatter hook. Security-relevant change is just
the two shell:true -> shell: process.platform === 'win32'
lines; everything else is whitespace/style.
The /welcome handler interpolates GSTACK_SLUG directly into the filesystem
path used to locate the project-local welcome page. Without validation, a
slug like "../../etc/passwd" would resolve to
~/.gstack/projects/../../etc/passwd/designs/welcome-page-20260331/finalized.html
— classic path traversal.

Not exploitable today: GSTACK_SLUG is set by the gstack CLI at daemon launch,
and an attacker would already need local env-var access to poison it. But
the gate is one regex (^[a-z0-9_-]+$), and a defense-in-depth pass costs us
nothing when the cost of being wrong is arbitrary file read via /welcome.

Fall back to the safe 'unknown' literal when the slug fails validation —
same fallback the code already uses when GSTACK_SLUG is unset. No behavior
change for legitimate slugs (they all match the regex).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Activity stream and inspector events SSE endpoints accepted the root
AUTH_TOKEN via `?token=` query param (EventSource can't send Authorization
headers). URLs leak to browser history, referer headers, server logs,
crash reports, and refactoring accidents. Codex flagged this during the
/plan-ceo-review outside voice pass.

New auth model: the extension calls POST /sse-session with a Bearer token
and receives a view-only session cookie (HttpOnly, SameSite=Strict, 30-min
TTL). EventSource is opened with `withCredentials: true` so the browser
sends the cookie back on the SSE connection. The ?token= query param is
GONE — no more URL-borne secrets.

Scope isolation (prior learning cookie-picker-auth-isolation, 10/10
confidence): the SSE session cookie grants access to /activity/stream and
/inspector/events ONLY. The token is never valid against /command, /token,
or any mutating endpoint. A leaked cookie can watch activity; it cannot
execute browser commands.

Components
  * browse/src/sse-session-cookie.ts — registry: mint/validate/extract/
    build-cookie. 256-bit tokens, 30-min TTL, lazy expiry pruning,
    no imports from token-registry (scope isolation enforced by module
    boundary).
  * browse/src/server.ts — POST /sse-session mint endpoint (requires
    Bearer). /activity/stream and /inspector/events now accept Bearer
    OR the session cookie, and reject ?token= query param.
  * extension/sidepanel.js — ensureSseSessionCookie() bootstrap call,
    EventSource opened with withCredentials:true on both SSE endpoints.
    Tested via the source guards; behavioral test is the E2E pairing
    flow that lands later in the wave.
  * browse/test/sse-session-cookie.test.ts — 20 unit tests covering
    mint entropy, TTL enforcement, cookie flag invariants, cookie
    parsing from multi-cookie headers, and scope-isolation contract
    guard (module must not import token-registry).
  * browse/test/server-auth.test.ts — existing /activity/stream auth
    test updated to assert the new cookie-based gate and the absence
    of the ?token= query param.

Cookie flag choices:
  * HttpOnly: token not readable from page JS (mitigates XSS
    exfiltration).
  * SameSite=Strict: cookie not sent on cross-site requests (mitigates
    CSRF). Fine for SSE because the extension connects to 127.0.0.1
    directly.
  * Path=/: cookie scoped to the whole origin.
  * Max-Age=1800: 30 minutes, matches TTL. Extension re-mints on
    reconnect when daemon restarts.
  * Secure NOT set: daemon binds to 127.0.0.1 over plain HTTP. Adding
    Secure would block the browser from ever sending the cookie back.
    Add Secure when gstack ships over HTTPS.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
The existing comment around the cookie-import-browser --remote-debugging-port
launch claimed "threat model: no worse than baseline." That's wrong on
Windows with App-Bound Encryption v20. A same-user local process that
opens the cookie SQLite DB directly CANNOT decrypt v20 values (DPAPI
context is bound to the browser process). The CDP port lets them bypass
that: connect to the debug port, call Network.getAllCookies inside Chrome,
walk away with decrypted v20 cookies.

The correct fix is to switch from TCP --remote-debugging-port to
--remote-debugging-pipe so the CDP transport is a stdio pipe, not a
socket. That requires restructuring the CDP WebSocket client in this
module and Playwright doesn't expose the pipe transport out of the box.
Non-trivial, deferred from the v1.6.0.0 wave.

This commit updates the comment to correctly describe the threat and
points at the tracking issue. No code change to the launch itself.
Follow-up: #1136.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Adds an explicit per-endpoint disposition table to the Security model
section, covering the v1.6.0.0 dual-listener refactor. Every HTTP
endpoint now has a documented local-vs-tunnel answer. Future audits
(and future contributors wondering "is it safe to add X to the tunnel
surface?") can read this instead of reverse-engineering server.ts.

Also documents:
  * Why physical port separation beats per-request header inference
    (ngrok behavior drift, local proxies can forge headers, etc.)
  * Tunnel surface denial logging → ~/.gstack/security/attempts.jsonl
  * SSE session cookie model (gstack_sse, 30-min TTL, stream-scope only,
    module-boundary-enforced scope isolation)
  * N2 non-goal for Windows v20 ABE via CDP port (tracking #1136)

No code changes.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Spawns the browse daemon as a subprocess with BROWSE_HEADLESS_SKIP=1 so
the HTTP layer runs without a real browser.  Exercises:

  * GET /health — token delivery for chrome-extension origin, withheld
    otherwise (the F1 + PR #1026 invariant)
  * GET /connect — alive probe returns {alive:true} unauth
  * POST /pair — root Bearer required (403 without), returns setup_key
  * POST /connect — setup_key exchange mints a distinct scoped token
  * POST /command — 401 without auth
  * POST /sse-session — Bearer required, Set-Cookie has HttpOnly +
    SameSite=Strict (the N1 invariant)
  * GET /activity/stream — 401 without auth
  * GET /activity/stream?token= — 401 (the old ?token= query param is
    REJECTED, which is the whole point of N1)
  * GET /welcome — serves HTML, does not leak /etc/passwd content under
    the default 'unknown' slug (E3 regex gate)

12 behavioral tests, ~220ms end-to-end, no network dependencies, no
ngrok, no real browser.  This is the receipt for the wave's central
'pair-agent still works + the security boundary holds' claim.

Tunnel-port binding (/tunnel/start) is deliberately NOT exercised here
— it requires an ngrok authtoken and live network.  The dual-listener
route allowlist is covered by source-level guards in
dual-listener.test.ts; behavioral tunnel testing belongs in a separate
paid-evals harness.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Architectural bump, not patch: dual-listener HTTP refactor changes the
daemon's tunnel-exposure model.  See CHANGELOG for the full release
summary (~950 words) covering the five root causes this wave closes:

  1. /health token leak over ngrok (F1 + E3 + test infra)
  2. /cookie-picker + /inspector exposed over the tunnel (F1)
  3. ?token=<ROOT> in SSE URLs leaking to logs/referer/history (N1)
  4. /welcome GSTACK_SLUG path traversal (E3)
  5. Windows v20 ABE elevation via CDP port (N2 — documented non-goal,
     tracked as #1136)

Plus the base PRs: SSRF gate (#1029), envelope sentinel escape (#1031),
DOM-channel hidden-element coverage (#1032), --from-file path validation
(#1103), and 2 commits from #1073 (@theqazi).

VERSION + package.json bumped to 1.6.0.0.  CHANGELOG entry covers
credits (@garagon, @Hybirdss, @HMAKT99, @theqazi), review lineage (CEO
→ Codex outside voice → Eng), and the non-goal tracking issue.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Addresses 4 findings from the Claude adversarial subagent on the
v1.6.0.0 security wave diff.  No user-visible behavior change; all
are defense-in-depth hardening of newly-introduced code.

1. GET /connect rate-limited (was POST-only) [HIGH conf 8/10]
   Attacker discovering the ngrok URL could probe unlimited GETs for
   daemon enumeration.  Now shares the global /connect counter.

2. ngrok listener leak on tunnel startup failure [MEDIUM conf 8/10]
   If ngrok.forward() resolved but tunnelListener.url() or the
   state-file write threw, the Bun listener was torn down but the
   ngrok session was leaked.  Fixed in BOTH /tunnel/start and
   BROWSE_TUNNEL=1 startup paths.

3. GSTACK_SKILL_ROOT path-traversal gate [MEDIUM conf 8/10]
   Symmetric with E3's GSTACK_SLUG regex gate — reject values
   containing '..' before interpolating into the welcome-page path.

4. SSE session registry pruning [LOW conf 7/10]
   pruneExpired() only checked 10 entries per mint call.  Now runs
   on every validate too, checks 20 entries, with a hard 10k cap as
   backstop.  Prevents registry growth under sustained extension
   reconnect pressure.

Tests remain green (56/56 in sse-session-cookie + dual-listener +
pair-agent-e2e suites).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Reflect the dual-listener tunnel architecture, SSE session cookies,
SSRF guards, and Windows v20 ABE non-goal across the three docs
users actually read for remote-agent and browser auth context:

- docs/REMOTE_BROWSER_ACCESS.md: rewrote Architecture diagram for
  dual listeners, fixed /connect rate limit (3/min → 300/min),
  removed stale "/health requires no auth" (now 404 on tunnel),
  added SSE cookie auth, expanded Security Model with tunnel
  allowlist, SSRF guards, /welcome path traversal defense, and
  the Windows v20 ABE tracking note.
- BROWSER.md: added dual-listener paragraph to Authentication and
  linked to ARCHITECTURE.md endpoint table. Replaced the stale
  ?token= SSE auth note with the HttpOnly gstack_sse cookie flow.
- CLAUDE.md: added Transport-layer security section above the
  sidebar prompt-injection stack so contributors editing server.ts,
  sse-session-cookie.ts, or tunnel-denial-log.ts see the load-bearing
  module boundaries before touching them.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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github-actions Bot commented Apr 22, 2026

E2E Evals: ✅ PASS

11/11 tests passed | $1.45 total cost | 12 parallel runners

Suite Result Status Cost
e2e-browse 2/2 $0.14
e2e-deploy 2/2 $0.31
e2e-qa-workflow 1/1 $0.61
llm-judge 4/4 $0.08
e2e-deploy 2/2 $0.31

12x ubicloud-standard-2 (Docker: pre-baked toolchain + deps) | wall clock ≈ slowest suite

garrytan and others added 2 commits April 21, 2026 21:19
make-pdf's browseClient wrote its --from-file payload to os.tmpdir(),
which is /var/folders/... on macOS. v1.6.0.0's PR #1103 cherry-pick
tightened browse load-html --from-file to validate against the
safe-dirs allowlist ([TEMP_DIR, cwd] where TEMP_DIR is '/tmp' on
macOS/Linux, os.tmpdir() on Windows). This closed a CLI/API parity
gap but broke make-pdf on macOS because /var/folders/... is outside
the allowlist.

Fix: mirror browse's TEMP_DIR convention — use '/tmp' on non-Windows,
os.tmpdir() on Windows. The make-pdf-gate CI failure on macOS-latest
(run 72440797490) is caused by exactly this: the payload file was
rejected by validateReadPath.

Verified locally: the combined-gate e2e test now passes after
rebuilding make-pdf/dist/pdf.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
…t agent event format

Two pre-existing bugs surfaced while running the full e2e suite on the
sec-wave branch.  Both pre-date v1.6.0.0 (same failures on main at
e23ff28) but blocked the ship verification, so fixing now.

### Bug 1: killAgent leaked stale per-tab state

`killAgent()` reset the legacy globals (agentProcess, agentStatus,
etc.) but never touched the per-tab `tabAgents` Map.  Meanwhile
`/sidebar-command` routes on `tabState.status` from that Map, not the
legacy globals.  Consequence: after a kill (including the implicit
kill in `/sidebar-session/new`), the next /sidebar-command on the
same tab saw `tabState.status === 'processing'` and fell into the
queue branch, silently NOT spawning an agent.  Integration tests that
called resetState between cases all failed with empty queues.

Fix: when targetTabId is supplied, reset that one tab's state; when
called without a tab (session-new, full kill), reset ALL tab states.
Matches the semantic boundary already used for the cancel-file write.

### Bug 2: sidebar-integration tests drifted from current event format

`agent events appear in /sidebar-chat` posted the raw Claude streaming
format (`{type: 'assistant', message: {content: [...]}}`) but
`processAgentEvent` in server.ts only handles the simplified types
that sidebar-agent.ts pre-processes into (text, text_delta, tool_use,
result, agent_error, security_event).  The architecture moved
pre-processing into sidebar-agent.ts at some point and this test
never got updated.  Fixed by sending the pre-processed `{type:
'text', text: '...'}` format — which is actually what the server sees
in production.

Also removed the `entry.prompt` URL-containment check in the
queue-write test.  The URL is carried on entry.pageUrl (metadata) by
design: the system prompt tells Claude to run `browse url` to fetch
the actual page rather than trust any URL in the prompt body.  That's
the URL-based prompt-injection defense.  The prompt SHOULD NOT
contain the URL, so the test assertion was wrong for the current
security posture.

### Verification

- `bun test browse/test/sidebar-integration.test.ts` → 13/13 pass
  (was 6/13 on both main and branch before this commit)
- Full `bun run test` → exit 0, zero fail markers
- No behavior change for production sidebar flows: killAgent was
  already supposed to return the agent to idle; it just wasn't fully
  doing so.  Per-tab reset now matches the documented semantics.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
@garrytan garrytan merged commit 54d4cde into main Apr 22, 2026
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3 participants