A Query.Farm VGI worker for DuckDB.

CVE/NVD Lookup with Offline CVSS Scoring in DuckDB

vgi-cve · a Query.Farm VGI worker

A VGI worker, written in Go, that looks up CVE / vulnerability data from the NVD 2.0 API and computes CVSS v3.1 scores — all exposed as DuckDB/SQL functions. It is a defensive vulnerability-management tool.

Built on the vgi-go SDK; speaks the VGI protocol over stdio. Catalog name: cve.

INSTALL vgi FROM community; LOAD vgi;

-- LOCATION is the path to the compiled worker binary.
ATTACH 'cve' AS cve (TYPE vgi, LOCATION '/path/to/vgi-cve-worker');

-- Offline CVSS math (no network):
SELECT cve.cvss_base_score('CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'); -- 9.8
SELECT cve.cvss_severity(9.8);                                              -- CRITICAL

-- Look up a CVE from the NVD API:
SELECT id, cvss_score, cvss_severity, cwe FROM cve.cve('CVE-2021-44228');

-- Keyword search (paginated, bounded to 100 results):
SELECT id, cvss_severity, published FROM cve.cve_search('log4j');

-- CVEs affecting a CPE name:
SELECT cve_id, cvss_score, cvss_severity
FROM cve.cpe_cves('cpe:2.3:a:apache:log4j:2.14.1:*:*:*:*:*:*:*');

Functions

There are two families: offline scalars (pure CVSS math, no network, deterministic) and table functions (live NVD 2.0 API lookups).

Offline CVSS scalars (no network)

Function	Returns	Description
cvss_severity(score DOUBLE)	VARCHAR	Map a base score to NONE/LOW/MEDIUM/HIGH/CRITICAL per the CVSS v3 bands.
cvss_base_score(vector VARCHAR)	DOUBLE	Compute the CVSS v3.1 base score from a vector string (e.g. CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H → 9.8). Implements the official v3.1 base equation, including the changed-scope path and the spec "Roundup".

NVD 2.0 table functions (network)

Function	Returns	Description
cve(cve_id)	id, description, cvss_score DOUBLE, cvss_severity VARCHAR, cvss_vector, published, last_modified, cwe	Fetch one CVE by ID (one row, or zero rows for a NULL id).
cve_search(keyword)	id, description, cvss_score, cvss_severity, published	Keyword search of CVE descriptions; paginated, bounded to 100 results.
cpe_cves(cpe)	cve_id, cvss_score, cvss_severity	CVEs affecting a CPE 2.3 name; paginated, bounded.

A CVE with no CVSS metrics yields a NULL cvss_score.

Named options (table functions)

Every table function accepts the same optional named arguments (DuckDB name := value syntax):

Option	Default	Meaning
base_url	the real NVD endpoint	Override the NVD 2.0 base URL (used to point at a mock/proxy).
api_key	''	NVD API key, sent as the apiKey header. Raises NVD's rate limit.

SELECT id, cvss_score
FROM cve.cve('CVE-2021-44228', api_key := 'your-nvd-key');

Behavior & robustness

• Offline first. cvss_severity and cvss_base_score make no network call and are fully deterministic — ideal for scoring vectors already in your data.
• NULL / absent input → no rows. A NULL id/keyword/cpe yields zero rows.
• No CVSS metrics → NULL score. Records still under analysis surface a NULL cvss_score rather than a misleading 0.
• Bounded & timed. Searches page through results but stop at 100 rows; every HTTP call has a 30 s timeout, so a slow or unreachable endpoint fails fast.
• Clear errors, never a crash or hang. HTTP 4xx/5xx, NVD rate-limiting (429), an unknown CVE id (404), or malformed JSON all surface as a clean DuckDB error.

Build

Requires Go 1.25+.

make build        # builds ./vgi-cve-worker and ./mockserver

The vgi-cve-worker binary speaks the VGI protocol over stdio; point a DuckDB ATTACH ... (TYPE vgi, LOCATION '…') at it.

Test

make test-unit    # pure-Go unit tests (offline CVSS + httptest mock NVD)
make test-sql     # haybarn-unittest SQL end-to-end against a local mock NVD
make test         # both

make test-sql needs haybarn-unittest on PATH:

uv tool install haybarn-unittest
export PATH="$HOME/.local/bin:$PATH"

It builds the worker and a small mock NVD server (cmd/mockserver, serving canned NVD 2.0 JSON), starts the mock on a free port, points the table functions at it via the base_url option, runs the suite, and stops the mock.

NVD API terms & rate limits

This worker calls the public NVD 2.0 vulnerability API operated by NIST. Please respect the NVD terms of use and rate limits: unauthenticated clients are throttled aggressively (roughly a handful of requests per rolling 30 s window). Request a free NVD API key and pass it via api_key := '…' to raise the limit. CVE data is courtesy of NIST/NVD; this project is not endorsed by or affiliated with NIST.

Licensing

• This worker is licensed MIT — see LICENSE.
• It uses only the Go standard library (net/http, encoding/json) for the NVD client and CVSS math, plus the vgi-go SDK (and its Arrow dependency) for the VGI protocol — see that repo for its terms.

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Authorship & License

Written by Query.Farm.

Copyright 2026 Query Farm LLC - https://query.farm