Windows Server 2025: Reinventing Active Directory and On-Prem Security

In an era where the cloud often hogs the limelight, Windows Server 2025 reminds us that local, on-premises solutions still offer rock-solid security and reliability. Far from being the relic of a bygone era, Active Directory (AD) remains a cornerstone of network infrastructure. The latest release from Microsoft not only embraces cloud-first innovations but also reinforces the importance—and relevance—of your on-premises deployment.

Active Directory: The Old Guard Gets a Modern Makeover​

Reports proclaiming the demise of Windows Active Directory are, to put it mildly, premature. Windows Server 2025 is bolstering AD with much-needed updates, ensuring that even in a hybrid world, on-premises security isn’t left in the dust. Here’s what’s new under the hood:

• Enhanced LDAP Security:
  Microsoft has long pushed for secure Lightweight Directory Access Protocol (LDAP) connections, yet many organizations still run legacy configurations. In Server 2025, mandatory LDAP encryption is enabled by default. This means all LDAP attributes—including user credentials—are safeguarded via encryption protocols, thwarting injection attacks and eavesdropping attempts that have plagued networks in the past.
• TLS 1.3 Integration:
  The latest version of Transport Layer Security (TLS) now supports LDAP connections, enhancing not just encryption but overall connection integrity. If you’re using LDAP over SSL (LDAPS) or issuing the StartTLS command, you'll notice improved protection granted by TLS 1.3— a protocol that has been quietly rolling out since mid-2022 across platforms like Windows 11 and Windows Server 2022.
  For the technically inclined, here's a quick peek under the hood:
• LDAP Server Side:

Use the Registry Editor to navigate to:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\NTDS\Parameters
Set the LdapDisableTLS1.3 value to 0 (enabled by default) or 1 to disable, then restart the Active Directory Domain Services service.

• LDAP Client Side:

Similarly, edit:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\LDAP
Change the DisableTLS1.3 value to 0 (default enabled) or 1 (disabled). The setting will apply on the next LDAP connection.

Randomized Machine Account Passwords: A Tougher Nut for Bruteforce Attacks​

Older machine accounts, often identified by the trailing “$”, have historically been vulnerable due to predictable password practices and infrequent changes. Windows Server 2025 addresses this head-on by introducing support for randomly generated passwords for machine accounts—effectively curbing brute-force attacks and making it markedly tougher for adversaries to exploit these accounts. If your network is still hosting "pre-Windows 2000" computer assignments, now’s the time to scrutinize them. Legacy devices are a liability, often relying on weak credentials that attackers can decipher with relative ease.

Encrypted Connections for Confidential Attributes​

In our increasingly data-sensitive world, encryption during transmission is more than a best practice—it’s a necessity. Server 2025 mandates encrypted connections for operations that involve confidential attributes. This additional security layer ensures that even if an attacker intercepts network traffic, the data remains indecipherable.

Hotpatching: Keeping Security Up Even When You’re Not Looking​

Server 2025 brings a robust hotpatching feature, allowing administrators to apply critical updates without resorting to cumbersome reboots. Initially available in the Windows Server 2022 Datacenter: Azure edition, hotpatching now extends its benefits through both physical servers and virtual machines across platforms like Hyper-V, VMware, and others. Leveraging Windows’ Virtualization Based Security standard, administrators can ensure that vital security updates are implemented swiftly, reducing exposure windows to potential threats. Hotpatching via Azure Arc further reinforces this advantage by seamlessly integrating management with Microsoft’s internal licensing service.

Migration and Upgrade Made Easy​

Migrating to Windows Server 2025 is more straightforward than ever:

• Upgrade Paths:
  You can now upgrade directly from Windows Server 2012 R2 and later—up to four versions at a time. This is a noteworthy change from previous limitations that only allowed skipping two versions at most.
• Forestry Considerations:
  To unlock features like a 32K database page size, you simply need to raise your forest level to Server 2025.
• In-Place Upgrades and Evaluation Conversions:
  Whether you’re moving from an evaluation copy to a retail version, from an older retail edition to something new, or even from volume licensing, the migration process has been streamlined to minimize disruption and maintain continuity.

Not Without Its Blemishes​

While Windows Server 2025 comes packed with enhancements, it’s worth remembering that no software release is without faults. Since its November release, multiple patches have been issued addressing a range of vulnerabilities: spoofing bugs, remote code execution flaws, information disclosure issues, and more. This underscores the ever-present need for vigilance—regularly review your event logs (especially event 4741 for unexpected machine account creations) and maintain an aggressive patch management strategy.

Keeping Your Environment Secure: Best Practices​

• Pre-Upgrade Testing:
  Use tools like IISCrypto to back up current settings before making changes, particularly when enforcing stronger cipher suites.
• Port Management:
  Ensure that port 636 is open on your Domain Controller for LDAPS connectivity.
• Network Review:
  Regularly audit your domain for any devices using outdated authentication methods and plan phased migrations.
• Stay Informed:
  Keep abreast of the latest patches and advisories, as even well-established products like Active Directory require continuous improvement in the face of evolving threats.

Conclusion​

Windows Server 2025 is a potent reminder that while cloud-based operations offer scalability and modern conveniences, on-premises security retains its critical role. With revamped Active Directory features, stringent encryption standards, and cutting-edge hotpatching capabilities, Microsoft is reinforcing the value of traditional deployments—ensuring that you don’t have to sacrifice local control for the sake of cloud agility.
As IT professionals and Windows users, it’s essential to integrate these best practices into your existing framework, balancing innovation with tried-and-true on-premises solutions. Whether you're managing a sprawling network or just a critical departmental server, the message is clear: the cloud is an excellent tool, but your on-prem investment is worth every bit of attention.
Feel free to share your experiences or ask questions about migrating to Windows Server 2025 on our forum—because when it comes to security, every insight counts!

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Source: CSO Online https://www.csoonline.com/article/3814617/the-cloud-is-not-your-only-option-on-prem-security-still-alive-and-well-in-windows-server-2025.html