Microsoft Deprecates Legacy VPN Protocols

It’s long overdue, but Microsoft has finally announced the formal deprecation of the Point-to-Point Tunnel Protocol (PPTP) and the Layer 2 Tunneling Protocol (L2TP) in Windows Server Routing and Remote Access (RRAS) Servers. Both protocols have long since been replaced with more secure alternatives such as the Secure Socket Tunneling Protocol (SSTP) and Internet Key Exchange version 2 (IKEV2). However, many organizations have RRAS servers configured using these legacy protocols to support ad-hoc, on-demand access for non-managed users and devices.

Deprecated Protocols

There are a few reasons why Microsoft has deprecated these legacy protocols. Consider the following.

PPTP

It’s been widely known for many years that PPTP is broken and terribly insecure. Using this VPN protocol today is tremendously risky.

L2TP

L2TP is still considered secure, for the most part. However, it has been replaced with IKEv2, which is more secure and efficient.

Future Support

Although Microsoft made the announcement recently, the protocols will still be included in Windows Server 2025 when released later this year. However, Microsoft may remove these protocols from future Windows Server releases.

Always On VPN

Those who have deployed Microsoft Always On VPN are likely already using modern, secure VPN protocols, so this deprecation announcement won’t impact them. Although PPTP and L2TP are technically supported with Always On VPN, they are not commonly configured.

Recommendations

Administrators using Windows Server RRAS for VPN access using PPTP are encouraged to migrate to another protocol immediately. Those continuing to use L2TP should consider migrating soon.

Additional Information

Always On VPN Protocol Recommendations for Windows Server RRAS

Always On VPN Security Updates August 2024

Today is the second Tuesday of the month, so Windows Server administrators everywhere know what that means – it’s Update Tuesday! For Always On VPN administrators in particular there are a few security updates that affect Windows Server Routing and Remote Access (RRAS), which is a popular VPN server used to support Always On VPN implementations. While many of these updates address Remote Code Execution vulnerabilities, non are considered critical.

RRAS Updates

This month there are six vulnerabilities disclosed affecting Windows Server RRAS.

CVE-2024-38120 – Windows RRAS Remote Code Execution Vulnerability (Important)

CVE-2024-38121 – Windows RRAS Remote Code Execution Vulnerability (Important)

CVE-2024-38128 – Windows RRAS Remote Code Execution Vulnerability (Important)

CVE-2024-38130 – Windows RRAS Remote Code Execution Vulnerability (Important)

CVE-2024-38154 – Windows RRAS Remote Code Execution Vulnerability (Important)

CVE-2024-38214 – Windows RRAS Remote Code Execution Vulnerability (Important)

Additional Updates

In addition to the updates addressing vulnerabilities in Windows Server RRAS, there are also updates available for the Windows Network Address Translation (NAT), Windows Transport Layer Security (TLS), and Windows IP Routing Management snapin that could potentially impact Always On VPN deployments.

Recommendations

None of the security vulnerabilities disclosed this month are critical. Although the RRAS vulnerabilities are remote code execution, exploitation is unlikely. However, administrators are encouraged to update their systems as soon as possible.

Additional Information

Microsoft August 2024 Security Updates

Microsoft Security Service Edge Now Generally Available

A few weeks ago, Microsoft announced the general availability of its Security Service Edge (SSE) offering, Global Secure Access (GSA). GSA encompasses Entra Internet Access, a cloud-based Secure Web Gateway, and Entra Private Access, a Zero Trust Network Access (ZTNA) solution for accessing private data and applications on-premises.

ZTNA vs. VPN

Entra Private Access will be a compelling alternative to traditional VPN solutions such as Windows Always On VPN. Where traditional VPNs grant the endpoint an IP address on the internal network, Entra Private Access provides more granular access and does not require the device to be directly connected to the network.

GSA Client

Administrators must install the GSA client on all endpoints using Entra Internet Access or Entra Private Access. Today, the client is available for Windows and Android devices. iOS and macOS clients are forthcoming.

Private Network Connector

The Entra Private Access solution relies on the Entra Private Network Connector. The Entra Private Network Connector is a software component installed on-premises that provides remote access connectivity. Previously, it was called the Azure AD Application Proxy. Essentially, it is the same technology extended to support TCP and UDP network access in addition to HTTP.

Limitations

Entra Private Access is the way of the future for secure remote access. However, today, there are still some important limitations associated with this technology.

Private DNS

Although Microsoft announced general availability for Entra Private Access, it still lacks the private DNS feature many organizations require to provide feature parity with their existing VPN. This feature is still in private preview at the time of this writing. Hopefully, Microsoft will release this feature soon.

Device Connection

Entra Private Access does not support device-based connections. This limits its capabilities for domain-joined devices. If your organization uses hybrid Entra join today, consider sticking with Always On VPN until you move to native Entra joined endpoints.

Licensing

Global Secure Access (Entra Private Access and Entra Internet Access) are included in the Microsoft Entra Suite license. More information about Entra licensing can be found here.

Additional Information

Microsoft Global Secure Access Now Generally Available

Microsoft Entra Global Secure Access (GSA) Overview

Microsoft Entra Security Service Edge (SSE) on the RunAs Radio Podcast

Microsoft Entra Plans & Pricing