Files
edgeguard-owasp-feed/CVE-CHANNEL.md
T
AndreandClaude Opus 5 6ca0cd5d20 Add the CVE channel document
cve.json carries virtual patches: rules written against a named
vulnerability, published as data so that every edge node enforces them
within the hour instead of waiting for an engine release. Engine 3.0.47 and
later fetch it hourly.

It starts empty, which is a valid state and says "no virtual patches at the
moment" — the engine accepts an empty rulesets list as of 3.0.47, and
publishing one is also how the whole channel stands down.

Separate from rulesets.json rather than part of it: each has its own
build_datetime, so each is applied or skipped on its own, and a mistake in
one cannot take out the other. Publishing a patch should not mean
republishing a 357KB mirror of the Core Rule Set.

CVE-CHANNEL.md documents the format, the param_names target, how severity
becomes the anomaly score, and the two mistakes worth avoiding: publishing a
rule for a CVE the engine already patches in code (both fire and the scores
add), and forgetting that there is no backtest for a patch written in the
hours after a disclosure — which is why withdrawal is a first-class
operation here.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01N5fpE6Gu4W6JoFMXyb7t7r
2026-10-22 14:45:39 +01:00

3.4 KiB

The CVE channel (cve.json)

This document carries virtual patches: rules written against a named vulnerability, published as data so that every edge node enforces them within the hour instead of waiting for an engine release.

It is deliberately a second document in this repository, not a second repository and not part of rulesets.json. Each has its own build_datetime, so each is skipped or applied on its own, and a mistake in one cannot take out the other.

Engine 3.0.47 and later fetch it hourly from:

https://git.artica.center/Andre/edgeguard-owasp-feed/raw/branch/main/cve.json

Publishing a patch

Add a rule to the single ruleset, bump build_datetime, commit, push. An unchanged build_datetime means every node skips the document without reading it, so the stamp is what makes a publish take effect.

{
  "build_datetime": "2026-10-22T13:00:00Z",
  "rulesets": [{
    "id": "edgeguard-cve",
    "name": "EdgeGuard CVE Virtual Patches",
    "version": "1",
    "source": "edgeguard-cve",
    "description": "Virtual patches for named vulnerabilities",
    "enabled": true,
    "priority": 1,
    "rules": [{
      "id": "CVE-2026-109618-01",
      "name": "PHP upload-progress field present",
      "pattern": "^php_session_upload_progress$",
      "targets": ["param_names"],
      "action": "block",
      "severity": "critical",
      "category": "cve",
      "cve": "CVE-2026-109618, CVE-2026-109619",
      "enabled": true,
      "references": ["https://nvd.nist.gov/vuln/detail/CVE-2026-109618"]
    }]
  }]
}

source must be edgeguard-cve. That is the source the channel owns and the only one it may clear, which is also what makes a rule withdrawable: remove it, bump the stamp, and it stops being enforced everywhere within the hour. Publishing an empty "rulesets": [] withdraws the lot.

Targets

The usual ones (uri, query, args, body, headers, user_agent, cookies, filename, all) plus:

  • param_names — the pattern is run against each parameter NAME on its own: query parameters, urlencoded body fields and multipart Content-Disposition names. An anchored pattern therefore anchors to one name, and a parameter whose value happens to be the string can never match. This is the shape CVE-2026-109618 needed and the reason it could not be written against args, where names and values arrive as one blob and ?note=PHP_SESSION_UPLOAD_PROGRESS would have been refused.

Write param_names patterns in lower case; both the original and the lowercased spelling of each name are tried.

Severity is the score

critical 5, high 4, medium 3, low 2, against a default anomaly threshold of 5. A patch that should refuse on its own is critical; one that should only contribute is medium or below. Nothing else sets the score.

Two things to get right

Do not publish a rule for a CVE the engine already patches in code. Both would fire on the same request, the anomaly score would be the sum, and the event would report one attack as two rules. TestPublishedFeedDoesNotDuplicateACompiledRule in the engine fails if this document names a CVE that ruleCVEReferences already covers.

A patch written in the hours after a disclosure is written against an advisory, not against traffic. There is no backtest. If one turns out to refuse something real, the remedy is to withdraw it — which is why withdrawal is a first-class operation here.