Connect with us

Hi, what are you looking for?

SecurityWeekSecurityWeek

Management & Strategy

Microsoft Publishes Guide to Securing Systems Vulnerable to Zerologon Attacks

Microsoft has published a support article to provide guidance on what organizations need to do to ensure that they are not exposed to attacks targeting the Zerologon vulnerability.

Microsoft has published a support article to provide guidance on what organizations need to do to ensure that they are not exposed to attacks targeting the Zerologon vulnerability.

Addressed on August 2020 Patch Tuesday, the flaw was identified in the Microsoft Windows Netlogon Remote Protocol (MS-NRPC) and can be abused by remote attackers to compromise Active Directory domain controllers and gain administrator access.

To exploit the flaw, which is tracked as CVE-2020-1472, an unauthenticated attacker would need to run a specially crafted application on a device on the network.

On September 18, the Department of Homeland Security’s Cybersecurity and Infrastructure Security Agency (CISA) issued an Emergency Directive requiring all federal agencies to apply the available patches within three days, and Samba also issued patches for the bug.

Last week, Microsoft said it was seeing adversaries attempting to exploit the vulnerability and this week CISA warned of similar attacks, urging administrators to patch all of their domain controllers.

In a guide aimed at administrators looking to keep their organization’s environment secure, Microsoft explains that patching for the bug is being performed in two stages: an initial deployment stage, starting with the August 11 release of patches, and an enforcement phase that will start on February 9, 2021.

To mitigate the vulnerability, Microsoft says, admins should apply the August update on all domain controllers and read-only domain controllers, monitor log events to identify any devices that might still make vulnerable connections, and address these non-compliant devices, and then enable enforcement mode to address the flaw.

Advertisement. Scroll to continue reading.

“The February 9, 2021 release marks the transition into the enforcement phase. The DCs will now be in enforcement mode regardless of the enforcement mode registry key. This requires all Windows and non-Windows devices to use secure RPC with Netlogon secure channel or explicitly allow the account by adding an exception for the non-compliant device,” Microsoft notes.

The tech giant also provides information on the type of log errors to look for to identify vulnerable Netlogon secure channel connections, what group policies to apply, and what happens following the installation of the August 11 patches or when the enforcement phase starts.

Related: Microsoft Explains How It Processes Vulnerability Reports

Related: Microsoft Patches Code Execution, Privilege Escalation Flaws in Azure Sphere

Related: Microsoft Patches 129 Vulnerabilities With September 2020 Security Updates

Written By

Ionut Arghire is an international correspondent for SecurityWeek.

Click to comment

Daily Briefing Newsletter

Subscribe to the SecurityWeek Email Briefing to stay informed on the latest threats, trends, and technology, along with insightful columns from industry experts.

Join security experts as they discuss ZTNA’s untapped potential to both reduce cyber risk and empower the business.

Register

Join Microsoft and Finite State for a webinar that will introduce a new strategy for securing the software supply chain.

Register

Expert Insights

Related Content

Application Security

Cycode, a startup that provides solutions for protecting software source code, emerged from stealth mode on Tuesday with $4.6 million in seed funding.

Vulnerabilities

Less than a week after announcing that it would suspended service indefinitely due to a conflict with an (at the time) unnamed security researcher...

CISO Strategy

SecurityWeek spoke with more than 300 cybersecurity experts to see what is bubbling beneath the surface, and examine how those evolving threats will present...

Data Breaches

OpenAI has confirmed a ChatGPT data breach on the same day a security firm reported seeing the use of a component affected by an...

CISO Conversations

Joanna Burkey, CISO at HP, and Kevin Cross, CISO at Dell, discuss how the role of a CISO is different for a multinational corporation...

CISO Conversations

In this issue of CISO Conversations we talk to two CISOs about solving the CISO/CIO conflict by combining the roles under one person.

Risk Management

The supply chain threat is directly linked to attack surface management, but the supply chain must be known and understood before it can be...

CISO Strategy

Security professionals understand the need for resilience in their company’s security posture, but often fail to build their own psychological resilience to stress.