sc-verifier

name	sc-verifier
description	False positive elimination and confidence scoring for all security findings
license	MIT
metadata	{"category":"security","version":"1.0.0"}

SC: Verifier — False Positive Elimination & Confidence Scoring

Purpose

The verifier skill processes all raw findings from Phase 2 vulnerability skills, eliminates false positives through multi-criteria analysis, assigns confidence scores, merges duplicate findings, and produces a curated list of verified security issues. This is the quality gate that ensures the final report contains actionable, high-signal findings.

Activation

Runs in Phase 3 of the pipeline, after all Phase 2 vulnerability skills have completed.

Input

All files matching security-report/*-results.md

Output

File: security-report/verified-findings.md

Verification Process

Step 1: Finding Collection

1. Read all *-results.md files from security-report/
2. Parse each finding into a structured format (title, severity, confidence, file, line, type, description)
3. Skip files containing "No issues found"
4. Create a unified finding list with source skill attribution

Step 2: Reachability Analysis

For each finding, determine if the vulnerable code is actually reachable:

Check if code is in an executable path:

• Is the file imported/included by any other file?
• Is the function called from an entry point (HTTP handler, CLI command, etc.)?
• Is the file part of the build output (not excluded by build config)?
• Trace the call chain from entry point to vulnerable code

Reachability scoring:

• Directly reachable from HTTP handler: +30 confidence
• Reachable through 1-2 function calls: +20 confidence
• Reachable through 3+ function calls: +10 confidence
• No clear call path found: -20 confidence
• Dead code (no imports/calls): -40 confidence

Step 3: Sanitization Check

For each finding involving user input, check if input is sanitized:

Sanitization indicators:

• Input passes through validation library (Zod, Joi, Pydantic, Bean Validation)
• Input is parameterized (prepared statements, ORM methods)
• Input passes through encoding/escaping function (htmlspecialchars, html/template, DOMPurify)
• Input is type-cast to safe type (parseInt, strconv.Atoi)

Sanitization scoring:

• No sanitization found: +0 (no change)
• Partial sanitization (some paths sanitized, others not): -10 confidence
• Full sanitization before reaching sink: -40 confidence
• Framework auto-sanitization active: -30 confidence

Step 4: Framework Protection Check

Check if the framework provides automatic protection against the reported vulnerability:

Vulnerability	Framework Protection
XSS	React JSX auto-escaping, Angular sanitization, Django template auto-escaping, Blade {{ }} escaping
SQL Injection	ORM parameterized queries (Prisma, GORM, Hibernate, EF), prepared statement wrappers
CSRF	Django CSRF middleware, Spring Security CSRF, Laravel VerifyCsrfToken, Express csurf
SSTI	Jinja2 sandbox mode, restricted template engines
Path Traversal	Framework static file servers with built-in path validation
Header Injection	Modern HTTP libraries that reject newlines in headers

Framework protection scoring:

• Framework auto-protection confirmed active: -30 confidence
• Framework protection exists but may be bypassed: -10 confidence
• No framework protection for this vulnerability type: +0

Step 5: Configuration Override Check

Check if configuration-level protections mitigate the finding:

• CSP headers mitigating XSS findings
• CORS strict configuration mitigating cross-origin findings
• WAF rules potentially blocking exploitation
• Network segmentation limiting SSRF impact
• File system permissions limiting path traversal impact

Configuration scoring:

• Strong configuration mitigation: -20 confidence
• Partial configuration mitigation: -10 confidence
• No configuration-level mitigation: +0

Step 6: Context Analysis

Determine the context of the vulnerable code:

Test code:

• File is in test/, tests/, __tests__/, spec/, *_test.go, *_test.py, *.test.ts
• File name contains test, spec, mock, fixture
• Finding in test code: -50 confidence (but keep as informational if it demonstrates a pattern)

Dead code:

• Function is never called from any reachable path
• File is not imported anywhere
• Code is commented out
• Finding in dead code: -40 confidence

Example/Documentation code:

• File is in examples/, docs/, demo/, sample/
• Finding in example code: -50 confidence

Generated code:

• File is in generated/, gen/, __generated__/
• File has // Code generated or @Generated annotation
• Finding in generated code: -30 confidence (flag for upstream fix)

Vendor/third-party code:

• File is in vendor/, node_modules/, third_party/
• Finding in vendored code: -40 confidence (should be covered by sc-dependency-audit)

Step 7: Duplicate Detection & Merging

Identify and merge findings that share the same root cause:

Duplicate criteria:

• Same file + same line number → merge, keep highest severity
• Same vulnerability type + same source variable → merge if same data flow
• Same vulnerability pattern across multiple files → group as one finding with multiple locations
• Findings from different skills about the same code → merge, note both perspectives

Merge rules:

• Keep the highest severity rating
• Keep the highest confidence score
• Combine descriptions from multiple skills
• List all affected files/lines

Step 8: Final Confidence Scoring

Calculate final confidence score for each finding:

Base confidence from the reporting skill: 0-100 Apply modifiers from steps 2-6:

final_confidence = base_confidence
    + reachability_modifier    (-40 to +30)
    + sanitization_modifier    (-40 to +0)
    + framework_modifier       (-30 to +0)
    + configuration_modifier   (-20 to +0)
    + context_modifier         (-50 to +0)

Clamp to 0-100 range.

Confidence classification:

• 90-100: Confirmed — Directly exploitable, high certainty
• 70-89: High Probability — Very likely vulnerable, minor conditions may apply
• 50-69: Probable — Likely vulnerable, additional manual verification recommended
• 30-49: Possible — May be a false positive, requires manual review
• 0-29: Low Confidence — Likely informational, marked as such in report

Step 9: Severity Recalculation

After confidence scoring, recalculate severity:

• Findings with confidence < 30: downgrade severity to "Info" regardless of original rating
• Findings with confidence 30-49: cap severity at "Medium"
• Findings with confidence 50-69: cap severity at "High"
• Findings with confidence 70+: keep original severity

Output Format

# Verified Security Findings

## Summary
- Total raw findings from Phase 2: {N}
- After duplicate merging: {N}
- After false positive elimination: {N}
- Final verified findings: {N}

## Confidence Distribution
- Confirmed (90-100): {N}
- High Probability (70-89): {N}
- Probable (50-69): {N}
- Possible (30-49): {N}
- Low Confidence (0-29): {N}

## Verified Findings

### VULN-001: {Title}
- **Severity:** Critical | High | Medium | Low | Info
- **Confidence:** {score}/100 ({classification})
- **Original Skill:** {skill-name}
- **Vulnerability Type:** CWE-XXX
- **File:** file/path:line
- **Reachability:** Direct | Indirect | Unknown
- **Sanitization:** None | Partial | Full
- **Framework Protection:** None | Partial | Active
- **Description:** Verified description
- **Verification Notes:** What was checked, why this is/isn't a false positive
- **Remediation:** How to fix

## Eliminated Findings (False Positives)
Brief list of eliminated findings with reason for elimination.

Common False Positive Patterns

1. ORM methods flagged as SQL injection — ORMs auto-parameterize; only raw() or RawSQL methods are risky
2. Template auto-escaping not recognized — React JSX, Django {{ }}, Blade {{ }} auto-escape by default
3. Test fixtures flagged as hardcoded secrets — test API keys, mock tokens are expected in test code
4. Localhost URLs flagged as SSRF — development URLs (localhost:3000) in config are not exploitable
5. Error messages in development config — debug=True in dev config, not in production
6. Type-safe languages reducing injection risk — Go's strconv, Rust's type system prevent many injection types
7. Environment variable reads flagged as secrets — os.Getenv("SECRET") reads at runtime, not hardcoded