Number: AV20-158
Date: 21 May 2020
On 20 May 2020 Microsoft released a security bulletin to address a high severity vulnerability affecting all current versions of Windows DNS servers. Exploitation of this vulnerability could allow a remote actor to use vulnerable servers as part of an amplification distributed denial of service (DDoS) and cause the exploited DNS server to also become non-responsive.
The Cyber Centre encourages users and administrators to review the following web link and follow the recommended mitigations:
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/ADV200009
Note to Readers
The Canadian Centre for Cyber Security (Cyber Centre) operates as part of the Communications Security Establishment. We are Canada’s national authority on cyber security and we lead the government’s response to cyber security events. As Canada's national computer security incident response team, the Cyber Centre works in close collaboration with government departments, critical infrastructure, Canadian businesses and international partners to prepare for, respond to, mitigate, and recover from cyber events. We do this by providing authoritative advice and support, and coordinating information sharing and incident response. The Cyber Centre is outward-facing, welcoming partnerships that help build a stronger, more resilient cyber space in Canada.