skills-firewall

Security firewall for skills that automatically blocks and filters malicious or potentially harmful skills. Use when: (1) Scanning skills for security threats. (2) Checking if a skill is safe to use. (3) Filtering multiple skills based on security rules. (4) Generating security reports for skills. (5) Managing allowed/blocked skill lists. (6) Reviewing skills before installation or execution.

Safety Notice

This listing is from the official public ClawHub registry. Review SKILL.md and referenced scripts before running.

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Install skill "skills-firewall" with this command: npx skills add huzibbs/skills-firewall

Skills Firewall

A security firewall that automatically blocks and filters malicious or potentially harmful skills by analyzing code patterns, detecting security threats, and enforcing security policies.

Quick Start

Scan a Single Skill

python scripts/scan_skill.py /path/to/skill

Check Firewall Decision

python scripts/firewall_check.py /path/to/skill

Generate Security Report

python scripts/generate_report.py /path/to/skills --format text

Core Workflows

1. Security Scanning

Scan skills for potential security threats:

# Scan single skill
python scripts/scan_skill.py ./my-skill

# Scan all skills in directory
python scripts/scan_skill.py ./skills

# JSON output for automation
python scripts/scan_skill.py ./my-skill --json

Threat Levels:

  • SAFE - No security concerns
  • LOW - Minor concerns, generally safe
  • MEDIUM - Moderate concerns, review recommended
  • HIGH - Significant risks, blocking recommended
  • CRITICAL - Severe threats, must block

2. Firewall Filtering

Check and filter skills based on security rules:

# Check single skill
python scripts/firewall_check.py ./my-skill

# Filter all skills
python scripts/firewall_check.py ./skills

# Add to allowed list
python scripts/firewall_check.py ./my-skill --allow

# Add to blocked list
python scripts/firewall_check.py ./my-skill --block

Actions:

  • allow - Skill passes firewall
  • warn - Skill has warnings but allowed
  • block - Skill is blocked
  • quarantine - Skill isolated for review

3. Security Reports

Generate comprehensive security reports:

# Text report
python scripts/generate_report.py ./skills

# JSON report
python scripts/generate_report.py ./skills --format json

# HTML report
python scripts/generate_report.py ./skills --format html --output report.html

Detection Categories

The firewall detects threats in these categories:

CategoryExamplesSeverity
Code Injectioneval(), exec(), import()HIGH
Command Executionsubprocess shell=True, os.system()HIGH
Credential ExposureHardcoded passwords, API keysCRITICAL
Network CommunicationHTTP requests, socket connectionsMEDIUM
File OperationsFile deletion, modificationMEDIUM
Deserializationpickle.loads, unsafe yaml.loadHIGH
Privilege Escalationsudo, chmod 777HIGH
ObfuscationBase64 decoding, encodingLOW

Configuration

Export/Import Config

# Export current config
python scripts/firewall_check.py ./skills --export-config firewall.yaml

# Use custom config
python scripts/firewall_check.py ./skills --config firewall.yaml

Config File Format

default_action: warn
allowed_skills:
  - skill-creator
  - weather
blocked_skills:
  - malicious-skill
quarantine_dir: ./quarantine
rules:
  - name: block_eval
    description: Block eval() usage
    patterns:
      - "eval("
    action: block
    enabled: true

Reference Documentation

Programmatic Usage

from scan_skill import scan_skill, ThreatLevel
from firewall_check import SkillsFirewall, ActionType

# Scan a skill
result = scan_skill("/path/to/skill")
print(f"Threat Level: {result.threat_level}")
print(f"Is Safe: {result.is_safe}")

# Use firewall
firewall = SkillsFirewall()
decision = firewall.check_skill("/path/to/skill")
print(f"Action: {decision.action}")
print(f"Reason: {decision.reason}")

# Manage lists
firewall.add_allowed_skill("trusted-skill")
firewall.add_blocked_skill("malicious-skill")

# Create custom rule
firewall.create_rule(
    name="block_custom_pattern",
    description="Block custom dangerous pattern",
    patterns=["dangerous_function("],
    action=ActionType.BLOCK
)

Best Practices

  1. Scan Before Use: Always scan new skills before installation
  2. Review Warnings: Investigate warning-level findings
  3. Update Rules: Keep detection patterns current
  4. Document Exceptions: Record why skills are allowed/blocked
  5. Regular Audits: Run periodic security scans
  6. Use Reports: Generate reports for compliance and review

Source Transparency

This detail page is rendered from real SKILL.md content. Trust labels are metadata-based hints, not a safety guarantee.

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