CVE-2017-8613 in Azure AD Connect
Summary
by MITRE
Azure AD Connect Password writeback, if misconfigured during enablement, allows an attacker to reset passwords and gain unauthorized access to arbitrary on-premises AD privileged user accounts aka "Azure AD Connect Elevation of Privilege Vulnerability."
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Analysis
by VulDB Data Team • 12/30/2020
The Azure AD Connect Password writeback vulnerability represents a critical elevation of privilege issue that emerged within Microsoft's cloud identity management infrastructure. This vulnerability specifically affects organizations that have implemented Azure AD Connect for hybrid identity management, where the service enables seamless synchronization between on-premises Active Directory and Azure Active Directory environments. The flaw manifests when administrators enable the password writeback feature without proper configuration, creating a security gap that can be exploited by malicious actors to gain unauthorized access to privileged on-premises Active Directory accounts.
The technical root cause of this vulnerability stems from improper access control implementation within the Azure AD Connect service architecture. When password writeback is enabled without appropriate security hardening, the system fails to properly validate authentication requests and authorization scopes. This misconfiguration allows attackers to manipulate the password reset process and potentially escalate privileges to gain access to accounts with elevated permissions within the on-premises Active Directory environment. The vulnerability operates at the intersection of cloud and on-premises identity management systems, leveraging the trust relationship established between Azure AD and on-premises AD to execute unauthorized operations.
From an operational impact perspective, this vulnerability poses significant risks to enterprise security postures and compliance requirements. Attackers who successfully exploit this vulnerability can reset passwords for arbitrary privileged accounts within the on-premises Active Directory, potentially gaining access to critical systems, sensitive data, and administrative functions. The attack vector typically involves leveraging the misconfigured password writeback functionality to perform password resets against accounts with elevated privileges, effectively bypassing traditional authentication controls. This capability enables attackers to establish persistent access within the enterprise network and potentially escalate their compromise to achieve broader system infiltration.
Organizations affected by this vulnerability should implement immediate mitigations including proper configuration of Azure AD Connect settings, implementation of least privilege access controls, and regular security assessments of hybrid identity configurations. The vulnerability aligns with CWE-284, which addresses improper access control issues, and maps to ATT&CK technique T1078 for valid accounts and T1531 for account access removal. Security teams should ensure that password writeback is only enabled when absolutely necessary, with proper network segmentation and monitoring in place to detect anomalous authentication patterns. Regular audits of Azure AD Connect configurations and implementation of multi-factor authentication for privileged accounts can significantly reduce the attack surface and prevent exploitation of this vulnerability.
The remediation approach requires comprehensive configuration review and implementation of security best practices for hybrid identity management. Organizations must ensure that Azure AD Connect is properly configured with appropriate access controls, that only authorized personnel have the ability to modify password writeback settings, and that appropriate monitoring and alerting mechanisms are in place to detect suspicious password reset activities. Additionally, implementing network-based controls such as firewalls and access control lists can limit exposure of the Azure AD Connect service to unauthorized network access, while regular security training for administrators can help prevent configuration errors that lead to this vulnerability.