Authorization / Constrained Delegation Vulnerability

Description

Constrained Delegation is a feature in Microsoft Active Directory that allows a service to impersonate users and access network resources on their behalf. This delegation of authentication and authorization is meant to enhance user experience and streamline application workflows. However, if not properly configured, Constrained Delegation can introduce a significant security risk. Attackers could potentially exploit this vulnerability to gain unauthorized access to network resources or escalate their privileges within the network.

Risk

The risk associated with the Constrained Delegation vulnerability lies in its potential to facilitate lateral movement and privilege escalation in a compromised Active Directory environment. If an attacker gains control over a service account with improperly configured Constrained Delegation, they can abuse the trust relationship between systems to impersonate users and access resources, including sensitive data and critical systems. This can lead to data breaches, unauthorized data modification, and further compromise of the network.

Mitigation

Only grant Constrained Delegation rights to service accounts that require them. Avoid giving unnecessary permissions to accounts, limiting the potential attack surface. Periodically review and update Constrained Delegation permissions. Remove unnecessary delegations and accounts that are no longer in use.