Description

A newly reported attack method shows how combining MITM6 with NTLM relay can give intruders total control over an Active Directory environment. The technique takes advantage of Windows devices automatically requesting IPv6 configurations, even in networks that don’t actively use the protocol. By setting up a fake DHCPv6 server, attackers can intercept those requests, manipulate DNS responses, and impersonate proxy services. This setup lets them capture authentication traffic and forward it to LDAP servers, creating unauthorized computer accounts that can be used to move deeper into the domain until administrative access is achieved. The real danger comes from several default features in Active Directory that are rarely changed. Windows machines, by design, prioritize IPv6 over IPv4, which provides an easy entry point for rogue services. Another default setting allows regular users to add a limited number of new machines to the domain without special approval. On top of that, machine accounts are able to alter certain delegation permissions, a weakness that can be exploited through Resource-Based Constrained Delegation (RBCD). When used together, these gaps allow attackers to impersonate high-privilege users and spread across the entire infrastructure. Organizations can lower their exposure by disabling IPv6 where it is not in use, applying LDAP signing and channel binding, and restricting machine account creation rights. Continuous monitoring for suspicious DHCP or DNS behavior is also critical for detecting early signs of compromise. Segmenting networks and enforcing strict privilege controls further limit how far an attacker can move. Addressing these overlooked defaults is key to preventing a complete domain takeover.