Microsoft Azure Active Directory Connect Authentication Bypass Vulnerability

Security Vulnerability

Released: Aug 10, 2021

Last updated: Aug 10, 2021

Assigning CNA
Microsoft
CVE.org link
CVE-2021-36949

Exploitability

The following table provides an exploitability assessment for this vulnerability at the time of original publication.

Publicly disclosed
No
Exploited
No
Exploitability assessment
Exploitation Less Likely

FAQ

What should I do to be protected against this vulnerability?

In addition to applying the updates in this CVE, you will need to disable NTLM as per the guidance as follows:

For Azure Active Directory Connect, see Prerequisites for Azure AD Connect For Azure Active Directory Connect Provisioning Agent, see Prerequisites for Azure AD Connect cloud sync

What must an attacker do to exploit this vulnerability

The attacker must be able to establish Man-in-the-middle between your Azure AD Connect server and a domain controller. The attacker also needs to possess domain user credentials to be able to exploit this vulnerability.

Acknowledgements

  • Eyal Karni with Crowdstrike
  • Sagi Sheinfeld with Crowdstrike
  • Yaron Zinar with CrowdStrike
Microsoft recognizes the efforts of those in the security community who help us protect customers through coordinated vulnerability disclosure. See Acknowledgements for more information.

Security Updates

To determine the support lifecycle for your software, see the Microsoft Support Lifecycle.

Release date Descending

Disclaimer

The information provided in the Microsoft Knowledge Base is provided "as is" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply.

Revisions

How satisfied are you with the MSRC Security Update Guide?