Azure Private Endpoint DNS Risks Can Cause Service DoS
🔒 Unit 42 researchers discovered an Azure Private Endpoint DNS behavior that can unintentionally or deliberately produce denial-of-service conditions for Azure services. In several scenarios — accidental internal, accidental vendor, and malicious actor — linking a Private DNS zone to a virtual network can force name resolution to the private zone and fail when no A record exists, breaking connectivity to otherwise public endpoints. Microsoft documents a partial mitigation (fallback to internet); alternatives include manually adding DNS records and performing comprehensive discovery with Resource Graph.
