DNS Security

What is DNS Security?

DNS security protects your domain from hijacking, spoofing, and other attacks. Proper DNS configuration includes DNSSEC, CAA records, and monitoring.

Security Impact

Severity: High

• Domain hijacking
• DNS spoofing
• Man-in-the-middle attacks
• Email interception
• Phishing attacks

How to Fix

1. Enable DNSSEC

# Check DNSSEC status
dig +dnssec yourdomain.com

# Enable via DNS provider (varies by provider)
# Cloudflare, Route53, etc. have one-click DNSSEC

2. Implement CAA Records

yourdomain.com. CAA 0 issue "letsencrypt.org"
yourdomain.com. CAA 0 issue "digicert.com"
yourdomain.com. CAA 0 issuewild ";"
yourdomain.com. CAA 0 iodef "mailto:security@yourdomain.com"

3. Set Proper TTL Values

# Balance between caching and flexibility
A record: TTL 300-3600 (5 min - 1 hour)
MX record: TTL 3600 (1 hour)

4. Monitor DNS Changes

Use DNS monitoring services:

• DNSViz
• DNSMon
• Cloudflare monitoring

Verification Steps

1. Check DNSSEC: dig +dnssec yourdomain.com
2. Verify CAA records: dig yourdomain.com CAA
3. Test DNS propagation
4. Monitor for unauthorized changes

Best Practices

• Enable two-factor authentication on DNS provider
• Use DNS provider with DDoS protection
• Regular DNS audits
• Document all DNS records
• Implement least-privilege access

Related Issues

• Subdomain Takeover
• Email Security
• SSL/TLS Security