Security Scan

Run ASH (Automated Security Helper) - a comprehensive security scanning tool that bundles multiple scanners into a unified interface. This skill includes delta detection to distinguish NEW findings (your changes) from PRE-EXISTING findings (inherited security debt).

Purpose

This skill performs security scanning using ASH, which includes:

• •Semgrep (SAST) - Static code analysis with custom rules support
• •Bandit (SAST) - Python-specific security analysis
• •Grype (SCA) - Dependency vulnerability scanning (no auth needed)
• •detect-secrets - Hardcoded secret detection
• •Checkov (IaC) - Terraform, CloudFormation, Kubernetes, Dockerfile scanning

What It Scans

Usage

/security-scan

Run this skill after implementing a story and staging changes, but BEFORE committing.

Scan Process

1. •Run ASH: Execute ASH scan against the project
2. •Load Baseline: Read state/{project}/security-baseline.json (pre-existing findings)
3. •Classify Findings: Compare each finding against baseline
   • •NEW: Finding not in baseline (introduced by your changes)
   • •PRE-EXISTING: Finding exists in baseline (inherited security debt)
4. •Report: Output both categories separately
5. •PASS/FAIL: Decision based on NEW findings only

Scan Execution

Step 1: Run ASH + Custom Semgrep Rules

# Create output directory
mkdir -p .ash/ash_output

# Run ASH in local mode (provides built-in scanners)
uvx --from git+https://github.com/awslabs/automated-security-helper.git@v3.1.5 \
  ash --mode local --source-dir . --output-dir .ash/ash_output

# Run custom semgrep rules separately (ASH doesn't pass custom config to semgrep)
if [ -f ".ash/rules/semgrep-rules.yml" ]; then
  uvx semgrep --config .ash/rules/semgrep-rules.yml --json --quiet . > .ash/ash_output/custom-semgrep.json 2>/dev/null || true
fi

Note: ASH runs semgrep with its built-in rules. Custom rules in .ash/rules/semgrep-rules.yml are run separately and merged with ASH results.

Step 2: Load Baseline

# Read baseline from Ralph Loop state directory
# The baseline was captured at the start of the session, before you made changes
cat "$RALPH_PROJECT_STATE_DIR/security-baseline.json" | jq '.'

The baseline file contains findings captured before you started working:

[
  {"file": "src/old-file.ts", "line": 15, "rule_id": "dangerous-eval", "severity": "ERROR"},
  ...
]

Step 3: Classify Findings

Compare current scan results (ASH + custom semgrep) against the baseline:

# Read ASH findings from OCSF format
ASH_FINDINGS=$(cat .ash/ash_output/reports/ash.ocsf.json | jq -c '[.[]? | .vulnerabilities[0] as $v | {file: $v.affected_code[0].file.path, line: $v.affected_code[0].start_line, rule_id: $v.cve.uid, severity: $v.severity, message: $v.desc}]')

# Read custom semgrep findings
CUSTOM_FINDINGS=$(cat .ash/ash_output/custom-semgrep.json 2>/dev/null | jq -c '[.results[]? | {file: .path, line: .start.line, rule_id: .check_id, severity: .extra.severity, message: .extra.message}]' || echo "[]")

# Merge all findings
CURRENT=$(echo "$ASH_FINDINGS" "$CUSTOM_FINDINGS" | jq -s 'add | unique_by(.file + ":" + (.line|tostring) + ":" + .rule_id)')

# Read baseline
BASELINE=$(cat "$RALPH_PROJECT_STATE_DIR/security-baseline.json" 2>/dev/null || echo "[]")

# A finding is NEW if it's not in the baseline
# Compare by: file + line + rule_id (signature matching)

Classification Logic:

• •NEW Finding: {file, line, rule_id} tuple NOT found in baseline
• •PRE-EXISTING Finding: {file, line, rule_id} tuple found in baseline AND file not modified in current changes

Step 4: Check Results

# Read aggregated results
cat .ash/ash_output/ash_aggregated_results.json | jq '.'

# Or read the summary
cat .ash/ash_output/reports/ash.summary.txt

Output Locations

ASH generates unified output in .ash/ash_output/:

Output Format

After running ASH and classifying findings, report in this format:

=== Security Scan Results ===
Status: PASS | FAIL (based on NEW findings only)

NEW Findings (N total):
- [ERROR] file:line - scanner/rule-id
  Message: Description of the vulnerability
  Fix: Recommended remediation

- [WARNING] file:line - scanner/rule-id
  Message: Description
  Fix: Recommendation

PRE-EXISTING Findings (M total):
  ⚠ These findings existed before your changes
  ⚠ They do NOT block your commit

- [ERROR] src/lib/old-file.ts:15 - dangerous-eval
  This file was not modified in your changes.
  Recommendation: Create GitHub issue for tracking.

Dependency Vulnerabilities (P total):
- [HIGH] package@version - CVE-YYYY-XXXXX
  Title: Vulnerability title
  Fix: Upgrade to version X.Y.Z

=== Summary ===
NEW: X findings (blocking)
PRE-EXISTING: Y findings (tracked, non-blocking)
Overall: PASS | FAIL

Decision Logic

PASS/FAIL is based on NEW findings only:

• •PASS: No NEW ERROR-level findings, no NEW HIGH severity vulnerabilities
• •FAIL: Any NEW ERROR-level finding OR any NEW HIGH severity vulnerability

Pre-existing findings are:

• •Reported for visibility
• •Logged to audit trail
• •Tracked via GitHub issues (if enabled)
• •NOT blocking - they don't cause FAIL

This allows you to proceed with legitimate work without being blocked by inherited security debt.

After Scanning

If PASS (new code is clean)

• •Proceed to commit
• •Update PRD to mark story complete
• •Pre-existing issues are tracked but don't block you

If FAIL (new code has issues)

1. •Read each NEW finding carefully (file:line provided)
2. •Apply fix using secure coding patterns from CLAUDE.md
3. •Stage the fixes: git add -A
4. •Re-run /security-scan
5. •Repeat until PASS (max 3 attempts)

If Still Failing After 3 Attempts

1. •DO NOT commit vulnerable code
2. •Create GitHub issue with findings (using gh CLI)
3. •Add note to progress.txt
4. •Move to next incomplete story

GitHub Issue Escalation

When stuck after 3 attempts on NEW findings:

gh issue create \
  --title "Security: [STORY_ID] - Unable to resolve [VULN_TYPE]" \
  --body "## Findings

[Paste scanner findings here]

## Attempted Fixes

1. [Description of first fix attempt]
2. [Description of second fix attempt]
3. [Description of third fix attempt]

## Context

Story: [STORY_ID] - [STORY_TITLE]
Files affected: [list files]

Generated by Securing Ralph Loop" \
  --label "security,ralph-escalation"

Pre-Existing Findings Tracking

Pre-existing vulnerabilities found in the baseline are:

1. •Logged in the audit trail with classification
2. •Reported to GitHub issues (by default)
3. •Displayed in session summary

You can disable GitHub issue creation for pre-existing findings:

./ralph-secure.sh --no-create-issues ...

Thresholds

ASH uses thresholds from .ash/ash.yaml:

global_settings:
  severity_threshold: MEDIUM
  fail_on_findings: true

Custom Rules

Custom Semgrep rules in .ash/rules/semgrep-rules.yml are run separately from ASH (ASH v3.1.5 doesn't honor the custom config option). The scan process automatically:

1. •Runs ASH (built-in semgrep + other scanners)
2. •Runs semgrep with .ash/rules/semgrep-rules.yml
3. •Merges and deduplicates findings

This gives you both ASH's comprehensive scanning AND your project-specific custom rules.

Troubleshooting

ASH not found

ASH runs via uvx, ensure UV is installed:

curl -LsSf https://astral.sh/uv/install.sh | sh

UV not found

brew install uv
# or
pip install uv

Permission denied

Ensure the output directory exists and is writable:

mkdir -p .ash/ash_output

Scanner-specific issues

Check individual scanner logs in .ash/ash_output/logs/

Baseline not found

If $RALPH_PROJECT_STATE_DIR/security-baseline.json doesn't exist:

• •All findings will be treated as NEW
• •This is expected on first run or if baseline wasn't captured
• •Run ralph-secure.sh which handles baseline creation automatically