/vuln-scan

Static vulnerability review of a source tree. Produces

VULN-FINDINGS.json

(+ a human-readable

.md

) that

/triage

ingests directly.

This skill does not execute code. It reads source and reasons about it. For execution-verified findings (ASAN crashes, reproducing PoCs), point the user at

vuln-pipeline run <target>

— see README Step 2.

Tool fallbacks. Prefer the dedicated Glob and Grep tools. Some sessions do not provision them —

allowed-tools

is a permission filter, not a loader, so listing them here does not make them appear. When Glob/Grep are unavailable, fall back to the read-only Bash commands whitelisted above:

rg --files <scope>

ls -R

for enumeration,

rg -n

grep -rn

for search,

wc

head

file

for sniffing. These are the ONLY permitted Bash commands; do not write helper scripts or pipe target content into a shell interpreter.

Arguments

```
<target-dir>
```
(required) — directory to scan. Relative or absolute.
```
--focus <area>
```
— scan only this focus area (repeatable). Skips recon.
```
--single
```
— no subagent fan-out; one sequential pass. Use on tiny targets or when debugging the prompt.
```
--extra <file>
```
— append the contents of
```
<file>
```
to the review brief (after the category list). Use to add org-specific vulnerability classes, compliance checks, or stack-specific patterns. Plain text; same shape as the category blocks below.
```
--no-score
```
— skip the Step 3b confidence pass (saves a round of subagents). Findings keep the scanner's self-reported confidence only.

Step 1 — Scope

Resolve
```
<target-dir>
```
. If it doesn't exist or has no source files, stop with an error.
Look for
```
<target-dir>/THREAT_MODEL.md
```
. If present, parse its section 3 "Entry points & trust boundaries" table and section 4 "Threats" table for focus areas and threat classes. This is the preferred scoping input.
If no THREAT_MODEL.md and no
```
--focus
```
: do a quick recon — list the source tree, read entry points and dispatch code, and propose 3-10 focus areas using the pattern
```
<subsystem> (<function/file>) — <key operations>
```
. Same shape as
```
harness/prompts/recon_prompt.py
```
.
If
```
--focus
```
was given, use exactly those.

Tell the user the focus areas you'll scan and the source-file count before fanning out.

Step 2 — Fan out

Unless

--single

, spawn one Task subagent per focus area in parallel. Cap at 10 concurrent. Each subagent gets the review brief below with its focus area filled in. On tiny targets (<15 source files), fall through to

--single

automatically.

Review brief (per subagent)

You are conducting authorized static security review of source code. Your
focus area: **{focus_area}**. Other agents cover other areas; duplication
is wasted effort.

TARGET: {target_dir}
TRUST BOUNDARY: {from THREAT_MODEL.md section 3, or "untrusted input → process memory"}

TASK: read the source in your focus area and identify candidate
vulnerabilities. This is static review — do NOT build, run, or probe
anything. Reason from the code.

REPORTING BAR: report anything with a plausible exploit path. Skip style
concerns, best-practice gaps, and purely theoretical issues with no attack
story at all — but if you're unsure whether something is real, REPORT IT
with a low confidence score rather than dropping it. A downstream triage
step does the rigorous verification; your job is to not miss things.

WHAT TO LOOK FOR:

  MEMORY SAFETY (C/C++ and unsafe/FFI blocks) — HIGH VALUE:
  - heap-buffer-overflow / stack-buffer-overflow / global-buffer-overflow
  - heap-use-after-free / double-free
  - integer overflow feeding an allocation or index
  - format-string bugs
  - unbounded recursion or allocation driven by untrusted size fields

  INJECTION & CODE EXECUTION — HIGH VALUE:
  - SQL / command / LDAP / XPath / NoSQL / template injection
  - path traversal in file operations
  - unsafe deserialization (pickle, YAML, native), eval injection
  - XSS (reflected, stored, DOM-based) — but see React/Angular note below

  AUTH, CRYPTO, DATA — HIGH VALUE:
  - authentication or authorization bypass, privilege escalation
  - TOCTOU on a security check
  - hardcoded secrets, weak crypto, broken cert validation
  - sensitive data (secrets, PII) in logs or error responses

  LOW VALUE — note briefly, keep looking:
  - null-pointer deref at small fixed offsets with no attacker control
  - assertion failures / clean error returns (correct handling, not a bug)

DO NOT REPORT (common false positives — skip even if technically present):
  - volumetric DoS / rate-limiting / resource-exhaustion — BUT unbounded
    recursion, algorithmic-complexity blowup, or ReDoS driven by untrusted
    input ARE reportable
  - memory-safety findings in memory-safe languages outside unsafe/FFI
  - XSS in React/Angular/Vue unless via dangerouslySetInnerHTML,
    bypassSecurityTrustHtml, v-html, or equivalent raw-HTML escape hatch
  - findings in test files, fixtures, build scripts, docs, or .ipynb
  - missing hardening / best-practice gaps with no concrete exploit
  - env vars and CLI flags as the attack vector (operator-controlled)
  - regex injection, log spoofing, open redirect, missing audit logs
  - outdated third-party dependency versions

{if --extra <file> was given: append its contents here verbatim}

For each finding you DO report, trace: where does the untrusted input
enter, what path reaches the sink, and what condition triggers it.

OUTPUT — one block per finding, nothing else:

<finding>
<id>F-{focus_idx:02d}-{n:02d}</id>
<file>{relative/path}</file>
<line>{line_number}</line>
<category>{heap-buffer-overflow | use-after-free | integer-overflow | sql-injection | command-injection | path-traversal | deserialization | xss | auth-bypass | hardcoded-secret | ...}</category>
<severity>{HIGH | MEDIUM | LOW}</severity>
<confidence>{0.0-1.0}</confidence>
<title>{one line}</title>
<description>{root cause, attacker control, trigger condition, data flow from entry to sink. Cite line numbers.}</description>
<exploit_scenario>{concrete attack: what input, from where, causing what outcome}</exploit_scenario>
<recommendation>{specific fix: parameterize the query, bounds-check before memcpy, etc.}</recommendation>
</finding>

SEVERITY: HIGH = directly exploitable → RCE, data breach, auth bypass.
MEDIUM = significant impact under specific conditions. LOW = defense-in-
depth.

If you find nothing reportable in your area after a thorough read, emit a
single <finding> with category=none and a one-line note of what you covered.

Step 3 — Collate

Collect
```
<finding>
```
blocks from all subagents. Drop
```
category=none
```
placeholders.
Light dedupe — if two findings cite the same
```
file:line
```
with the same category, keep the one with the longer description and note the duplicate id. (Heavy dedupe is
```
/triage
```
's job; don't over-engineer here.)
Assign stable ids
```
F-001
```
,
```
F-002
```
, ... in (severity desc, file, line) order.

Step 3b — Confidence pass (skip if

--no-score

)

A cheap second-opinion read that ranks findings by signal quality. Nothing is dropped — this pass calibrates

confidence

so humans and

/triage

see high-signal findings first. Spawn one Task subagent per finding in parallel with the brief below. Shallow: re-read and score, not a full reachability trace.

Scoring brief (per finding)

You are giving ONE candidate security finding an independent confidence
score. You are NOT deciding whether to keep it — every finding is kept.
You are deciding how likely it is to survive rigorous triage.

FINDING:
{the full <finding> block}

TARGET: {target_dir} (you may Read/Grep inside it; do NOT execute)

STEP 1 — Re-read the cited code. Open {file} around line {line}. Does the
code actually do what the description claims?

STEP 2 — Check against common false-positive patterns (volumetric DoS,
memory-safe language, test/fixture/doc file, framework auto-escape, env-var
vector, missing-hardening-only, regex/log injection, outdated dep). A match
lowers confidence sharply but does not auto-zero it.

STEP 3 — Score 1-10 that this is a real, actionable vulnerability:
  1-3  likely false positive or noise
  4-5  plausible but speculative
  6-7  credible, needs investigation
  8-10 high confidence, clear pattern

OUTPUT (exactly this, nothing else):
  CONFIDENCE: <1-10>
  REASON: <one line>

Resolve: overwrite each finding's

confidence

with the score (normalized to 0.0-1.0) and attach

confidence_reason

. Re-sort findings by (

confidence

desc,

severity

desc,

file

line

) and reassign ids

F-001..

in that order. Compute

low_confidence_count

= findings with confidence < 0.4, for the summary line.

Step 4 — Write output

Write both files to

<target-dir>/

VULN-FINDINGS.json
— the

/triage

ingest shape:

json

{
  "target": "<target-dir>",
  "scanned_at": "<iso8601>",
  "focus_areas": ["..."],
  "findings": [
    {
      "id": "F-001",
      "file": "relative/path.c",
      "line": 123,
      "category": "heap-buffer-overflow",
      "severity": "HIGH",
      "confidence": 0.9,
      "title": "...",
      "description": "...",
      "exploit_scenario": "...",
      "recommendation": "...",
      "confidence_reason": "..."
    }
  ],
  "summary": {"total": 0, "high": 0, "medium": 0, "low": 0, "low_confidence": 0}
}

Findings are sorted by

confidence

desc (then severity, file, line), so the top of the file is the highest-signal material.

VULN-FINDINGS.md
— human-readable: a summary table (id | severity | category | file:line | title), then one

### F-NNN

section per finding with the full description.

Step 5 — Hand back

Tell the user:

Counts: N findings (H/M/L split, X low-confidence), across K focus areas, from M source files.
Top 3 by confidence, one line each.

Next step:

> /triage <target-dir>/VULN-FINDINGS.json --repo <target-dir>

Remind: these are static candidates, not verified. For execution-verified crashes,
```
vuln-pipeline run <target>
```
(README Step 2).

Constraints

Never execute target code. No Bash, no builds, no
```
docker
```
, no network. If the user asks you to "reproduce" or "confirm with a PoC," decline and point at
```
vuln-pipeline
```
.
Don't fabricate line numbers. Every
```
file:line
```
you emit must be something you Read or Grep'd. If unsure of the exact line, cite the function and say so in the description.
Stay in
<target-dir>
. Don't follow symlinks or
```
..
```
out of it.
Findings are candidates for
```
/triage
```
, not final verdicts. This skill never drops a finding — Step 3b only ranks.
```
/triage
```
does the rigorous N-vote verification and is where false positives actually get removed.

Provenance

The focus-area recon pattern and memory-safety quality tiers are lifted from this repo's own

harness/prompts/find_prompt.py

and

harness/prompts/recon_prompt.py

— the same logic the autonomous pipeline uses, applied statically. The broader category menu, DO-NOT-REPORT exclusions, per-finding confidence pass, and

exploit_scenario

recommendation

output fields are adapted from

anthropics/claude-code-security-review

/security-review

command.

vuln-scan

NPX Install

Tags

SKILL.md Content

/vuln-scan

Arguments

Step 1 — Scope

Step 2 — Fan out

Review brief (per subagent)

Step 3 — Collate

Step 3b — Confidence pass (skip if
`--no-score`
)

Scoring brief (per finding)

Step 4 — Write output

Step 5 — Hand back

Constraints

Provenance

vuln-scan

NPX Install

Tags

SKILL.md Content

/vuln-scan

Arguments

Step 1 — Scope

Step 2 — Fan out

Review brief (per subagent)

Step 3 — Collate

Step 3b — Confidence pass (skip if --no-score)

Scoring brief (per finding)

Step 4 — Write output

Step 5 — Hand back

Constraints

Provenance

Step 3b — Confidence pass (skip if
`--no-score`
)