Microsoft has clarified the steps customers should take to ensure their devices are protected against ongoing attacks using Windows Server exploits Zerologon (CVE-2020-1472).
Η company επικαιροποίησε τη δημοσίευση που είχε εκδώσει, όταν οι πελάτες της την βρήκαν αρκετά δύσκολη και δεν ήταν σίγουροι εάν η application of the update was enough to protect vulnerable Windows Server devices from the attacks.
In a step-by-step approach, the updated post explains the exact steps administrators should take to ensure that their machines are protected in the event of an incoming attack designed to exploit Zerologon.
Microsoft outlines the following plan for Windows administrators to follow when implementing “CVE-2020-1472 | The security update of Netlogon Elevation of Privilege Vulnerability released as part of it Patch Tuesday in August 2020:
- UPDATED your Domain Controllers with an update released August 11, 2020 or later.
- FIND which devices are making vulnerable connections by monitoring event logs.
- ADDRESS non-compliant devices making vulnerable connections.
- ENABLE enforcement mode to address CVE-2020-1472 in your environment.
The Zerologon vulnerability
CVE-2020-1472 is a critical security vulnerability with a score of 10/10. It was named Zerologon by the security company Secura and when exploited, it allows intruders to increase privileges in an administrator domain.
This makes it very easy for them to take control of the domain, as they can change each user's password and run whatever command they want.
The security update released by Microsoft in August may cause authentication issues on some of the affected devices, and the company has released the Zerologon patch in two stages.
The first was released on August 11 as an update security version which will prevent Windows Active Directory domain controllers from using insecure RPC communication.
It also records authentication requests from non-Windows devices that do not use secure RPC channels to give administrators time to correct errors.
From February 9, 2021, as part of the Patch Tuesday updates, Microsoft will release another update that will enable a enforcement feature that will require all network devices to use secure RPCs, unless expressly permitted by administrators.
We have updated the KB article for CVE-2020-1472 to provide clarity on customer actions to ensure they are protected. See details here: https://t.co/l4MwY9DFvt
- Security Response (@msftsecresponse) September 28, 2020
Ongoing Zerologon attacks
Last week, Microsoft warned administrators to urgently implement security updates for Zerologon after discovering that they are being used during attacks.
Microsoft Threat Intelligence analyst Kevin Beaumont confirmed that the attacks began on September 26, with attackers successfully exploiting a vulnerable honeypot on an Active Directory server using a Zerologon exploit.
Yesterday, security researchers at Cisco Talos also warned of "a sharp increase in vulnerability in Microsoft CVE-2020-1472".
