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wedabrowedabro/bro-skills/.agents/skills/fix-security-vulnerabilities-with-strix/SKILL.md

fix-security-vulnerabilities-with-strix

Skill3 starsChanged 45 days agoMITView on GitHub

Fix security vulnerabilities found by a Strix pentest (open-source CLI or app.strix.ai cloud) — triage by severity, patch the root cause rather than the symptom, and re-run Strix to prove each fix actually closes the exploit. Handles injection, XSS, SSRF, broken access control, IDOR, and other validated findings. Use after a Strix scan reports findings, or when the user asks to remediate, patch, or fix security issues from a strix_runs report, vulnerabilities.json, findings.sarif, or a cloud scan.

We split this skill into the rules it gives an agent

4 rules. About 0 are common, 3 are distinctive, and 1 is very specific to this project.

  • ≈0

    Common · estimate

    Many files like this have a rule of this kind.

  • ≈3

    Distinctive · estimate

    This author's own choices. Worth a look.

  • 1

    Very specific

    Tied to their project's names, files or tools. Probably skip.

  • Common
  • Distinctive
  • Very specific
  1. Distinctive:

    Prefer the framework's built-in defense (ORM parameterization, template auto-escaping, CSRF middleware, centralized authz) over ad-hoc …

    line 31
  2. Very specific:

    Keep the diff minimal and apply the repo's existing patterns.

    line 32
  3. Distinctive:

    After fixing, re-scan scoped to the fixed area and confirm the finding is gone.

    line 38
  4. Distinctive:

    Run the project's own test suite to make sure the fix doesn't break behavior.

    line 73

≈ “Common” is an estimate: at least 1 in 5 of the 308,232 skill files we read have a rule of the same kind, not the same words. “Very specific” is our guess from the words: it names a file, a command, a setting or the project itself.

Keep what fits and drop the rest. Your version, ready for your agents.
Files
SKILL.md

Fix Strix findings and verify

Turn validated Strix findings into minimal, correct fixes — and prove they work by re-scanning.

1. Triage

Get the findings from wherever the scan ran:

  • OSS CLI — artifacts in strix_runs/<run-name>/:
    • vulnerabilities/*.md — one finding per file: description, severity, PoC steps or script, affected code locations, remediation guidance.
    • vulnerabilities.json — the same findings as JSON (ids, severity, CWE/CVE, code_locations with fix_before/fix_after suggestions when available).
  • Cloud (app.strix.ai) — fetch the scan's vulnerabilities[] via GET /api/v1/scans/{scanId} (or GET /api/v1/vulnerabilities org-wide). Each carries severity, cwe, endpoint, method, impact, technical_analysis, poc_description, poc_script_code and, for code findings, code_file/code_diff/code_before/code_after. See the managed-pentesting-with-strix skill for auth.

Order work by severity: critical → high → medium → low. Every Strix finding was validated with a working proof-of-concept, so do not dismiss findings as false positives without re-testing the PoC yourself.

2. Fix

For each finding:

  1. Reproduce it with the PoC from the finding file when feasible.
  2. Fix the root cause, not the specific payload (e.g. parameterize all queries, don't blocklist one string; enforce authorization in the handler, don't hide the endpoint).
  3. Prefer the framework's built-in defense (ORM parameterization, template auto-escaping, CSRF middleware, centralized authz) over ad-hoc sanitization.
  4. Keep the diff minimal and apply the repo's existing patterns. Finding files often include fix_before/fix_after snippets — use them as a starting point, not verbatim.

Common finding classes and expected fixes: injection → parameterization/escaping at the sink; IDOR/broken access control → object-level authorization checks; SSRF → allowlist + block internal ranges; XSS → context-aware output encoding + CSP; secrets exposure → rotate the secret AND remove it from code/history; auth issues → fix the server-side check (never client-side).

3. Verify by re-running Strix

After fixing, re-scan scoped to the fixed area and confirm the finding is gone. Verify in whichever environment you scanned (or both):

OSS CLI:

# Re-test just the changed files (fast). Resolve the repo's real default
# branch instead of assuming origin/main (many repos use master/develop).
# Avoid the current branch's own upstream as the base — its merge base with
# HEAD would be HEAD, giving an empty diff and a falsely clean result.
DIFF_BASE=$(git symbolic-ref --quiet --short refs/remotes/origin/HEAD 2>/dev/null)
# origin/HEAD can be a dangling symbolic ref — keep it only if its target exists.
git rev-parse --verify --quiet "$DIFF_BASE" >/dev/null 2>&1 || DIFF_BASE=""
if [ -z "$DIFF_BASE" ]; then
  for b in origin/main origin/master origin/develop; do
    git rev-parse --verify --quiet "$b" >/dev/null && DIFF_BASE="$b" && break
  done
fi
# No silent fallback: a guess like HEAD~1 would cover only the last commit of a
# multi-commit fix branch. If no base resolves, ask the user for the base branch
# (or use the focused --instruction verification below, which needs no diff base).
[ -n "$DIFF_BASE" ] || { echo "Set DIFF_BASE to the branch your fix will merge into." >&2; exit 1; }
strix -n -t ./ --scan-mode quick --scope-mode diff --diff-base "$DIFF_BASE" --max-budget 5

# Or re-test with the original finding as focus (no diff base needed)
strix -n -t ./ --instruction "Verify the SQL injection in app/api/search.py is fixed. Original PoC: <poc>" --max-budget 5

Exit codes: 2 = findings remain (read the new strix_runs/<run>/vulnerabilities/ and iterate); 0 = clean for what was analyzed. Before trusting a 0, confirm the run wasn't cut short — check run.json for a completed status and compare its llm_usage.cost with --max-budget: a hard budget stop leaves status: "stopped", but a run that wrapped up on a budget warning records "completed" with partial coverage. Give verification enough budget to finish, and prefer re-running the specific PoC as the ground-truth signal.

Cloud: rerun with the same config and re-poll, then confirm the finding no longer appears:

new_id=$(curl -sS "$BASE/scans/$scan_id/rerun" "${auth[@]}" -X POST | jq -r .scan_id)
# poll GET /scans/$new_id until completed, then check its vulnerabilities[]

Or, if the cloud scan came from a repo/PR, trigger a fresh PR review on the fix branch (POST /pr-reviews/start). The platform also retests a single finding directly: POST /api/v1/vulnerabilities/{vulnerabilityId}/retest.

  • Also re-run the PoC manually when it is a simple request/script — fastest signal.
  • Run the project's own test suite to make sure the fix doesn't break behavior.

4. Report

Summarize per finding: severity, root cause, fix applied (file:line), verification result (re-scan clean / PoC no longer reproduces). Never include live secrets in the report; if a secret leaked, state that rotation is required.

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