All posts tagged RCE

Always On VPN Security Updates July 2026

Microsoft released the July 2026 Windows security updates today, including several fixes that directly affect Always On VPN deployments. This month’s release addresses vulnerabilities in the Secure Socket Tunneling Protocol (SSTP), Internet Key Exchange (IKE), and the Routing and Remote Access Service (RRAS), making it an important update for organizations using Always On VPN.

SSTP Remote Code Execution

The highest-priority issue for Always On VPN administrators is a Remote Code Execution (RCE) vulnerability affecting the Secure Socket Tunneling Protocol (SSTP). SSTP is commonly used for Always On VPN user tunnel connections. Because SSTP is, by design, exposed directly to the Internet, vulnerabilities affecting this protocol deserve immediate attention. Microsoft rates this vulnerability as Critical with a CVSS base score of 8.1.

CVE-2026-50694 – Windows SSTP Remote Code Execution Vulnerability

IKE Vulnerabilities

These vulnerabilities primarily affect IKE-based VPN connections and could allow an attacker to disrupt VPN connectivity using specially crafted packets. While Microsoft rates these vulnerabilities as Important rather than Critical, organizations should still plan to deploy these updates promptly.

CVE-2026-50721 – IKEv1 Denial of Service via RSA-SHA1 authentication payload

CVE-2026-50722 – IKEv2 Denial of Service via RSA-SHA1 authentication payload

CVE-2026-12413 – IKEv2 Denial of Service via malformed fragmentation

CVE-2026-50696 – IKE Protocol Denial of Service Vulnerability

RRAS Vulnerabilities

The July 2026 security updates also address several vulnerabilities in the Windows Server Routing and Remote Access Service (RRAS). All are rated Important by Microsoft.

CVE-2026-57096 – Windows RRAS Elevation of Privilege Vulnerability

CVE-2026-49791 – Windows RRAS Elevation of Privilege Vulnerability

CVE-2026-50451 – Windows RRAS Elevation of Privilege Vulnerability

Summary

The SSTP RCE vulnerability is particularly concerning because the service is typically exposed to the Internet and could allow an unauthenticated attacker to execute code remotely. Organizations should prioritize deployment of this update. The IKE and RRAS vulnerabilities are rated Important and can generally be addressed during the next scheduled maintenance window, although administrators should avoid unnecessary delays in applying these updates.

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by Richard M. Hicks on July 14, 2026  •  Permalink
Posted in Always On VPN, AOVPN, Enterprise, enterprise mobility, Hotfix, IKEv2, Infrastructure, Microsoft, Operational Support, Patch Tuesday, RCE, Remote Access, routing and remote access service, RRAS, Secure Socket Tunneling Protocol, Security, Security Update, SSTP, Update, VPN, Vulnerability, Windows 10, Windows 11, Windows Server 2016, Windows Server 2019, Windows Server 2022, Windows Server 2025
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Posted by Richard M. Hicks on July 14, 2026

https://directaccess.richardhicks.com/2026/07/14/always-on-vpn-security-updates-july-2026/

Always On VPN IKEv2 Security Vulnerability April 2026

Microsoft published its Security Updates for April 2026 today, and the good news is that there are no Windows Server Routing and Remote Access (RRAS) vulnerabilities this month. However, they disclosed a critical remote code execution (RCE) vulnerability that impacts deployments using Internet Key Exchange version 2 (IKEv2).

IKE Service Extensions RCE

CVE-2026-33824 addresses a security vulnerability in the Windows Internet Key Exchange (IKE) Service Extensions. This vulnerability is a Remote Code Execution (RCE) vulnerability, with a CVSS 3.1 base score of 9.8 (Critical). Always On VPN implementations that use the device tunnel or IKEv2 for the user tunnel are affected.

Impact

This vulnerability presents a unique challenge to Always On VPN administrators as IKEv2 is required to support device tunnel connections. Some implementations also use IKEv2 for the user tunnel. In either case, the vulnerable VPN server, often domain-joined, is reachable from the Internet, greatly increasing the attack surface and exposure to this vulnerability.

Recommendations

For deployments that use IKEv2 (device or user tunnel), administrators should update their RRAS server as soon as possible to protect against potential attacks on this service.

Not Using IKEv2?

If you are not using the device tunnel or IKEv2 for the user tunnel, ensure the following IKEv2 ports are blocked at the edge firewall.

  • Inbound UDP port 500 (IKE)
  • Inbound UDP port 4500 (IKE NAT-T)

In addition, consider disabling IKEv2 on the RRAS server by opening an elevated command window and running the following command.

netsh.exe ras set wanports device = "WAN Miniport (IKEv2)" rasinonly = disabled ddinout = disabled ddoutonly = disabled maxports = 0

Optionally, you can use the Routing and Remote Access management console (rrasmgnt.msc) to perform this task.

  1. Right-click on Ports and choose Properties.
  2. Select WAN Miniport (IKEv2).
  3. Click Configure.
  4. Uncheck Remote access connections (inbound only).
  5. Uncheck Demand-dial routing connection (inbound and outbound).
  6. Enter 0 in the Maximum ports field.
  7. Click Ok.

Additional Information

Microsoft Security Updates for April 2026

CVE-2026-33824 – Windows Internet Key Exchange (IKE) Service Extension RCE

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by Richard M. Hicks on April 14, 2026  •  Permalink
Posted in Always On VPN, AOVPN, CVE, device tunnel, Enterprise, enterprise mobility, IKEv2, Infrastructure, Microsoft, Patch Tuesday, RCE, Remote Access, routing and remote access service, RRAS, Security, Security Update, Update, user tunnel, VPN, Vulnerability, Windows 10, Windows 11, Windows Server 2016, Windows Server 2019, Windows Server 2022, Windows Server 2025
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Posted by Richard M. Hicks on April 14, 2026

https://directaccess.richardhicks.com/2026/04/14/always-on-vpn-ikev2-security-vulnerability-april-2026/

Always On VPN Security Updates July 2025

Patch Tuesday has arrived, and, unlike last month, it’s a busy month for Always On VPN administrators. The June 2025 Microsoft security updates address a whopping 16 (!) vulnerabilities in the Windows Routing and Remote Access Service (RRAS). Notably, DirectAccess administrators are once again impacted by a critical vulnerability in the Windows KDC Proxy Service (KPSSVC) this month.

RRAS

As stated previously, this month’s update addresses 16 unique CVEs in Windows Server RRAS. All are memory-related buffer overflows and out-of-bounds reads, indicating that a security researcher was recently probing for vulnerabilities in RRAS.

While all the above CVEs are Remote Code Execution (RCE) and Information Disclosure vulnerabilities, none are rated as Critical; all are rated as Important. This means exploitation is unlikely, but administrators are encouraged to update as soon as possible.

KDC Proxy

This month’s security update includes another Critical RCE in the Windows KDC Proxy Service (KPSSVC).

The KDC Proxy is enabled by default when DirectAccess is configured. By design, this means the service is exposed to the public Internet, posing a significant risk to organizations using DirectAccess for secure remote access. Administrators are urged to update their systems immediately to avoid compromise.

Additional Information

Microsoft July 2025 Security Updates

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by Richard M. Hicks on July 8, 2025  •  Permalink
Posted in Always On VPN, AOVPN, authentication, CVE, DirectAccess, KDC Proxy, Microsoft, Patch Tuesday, routing and remote access service, RRAS, Security, Security Update, Update, VPN, Vulnerability, Windows 10, Windows Server 2016, Windows Server 2019, Windows Server 2022, Windows Server 2025
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Posted by Richard M. Hicks on July 8, 2025

https://directaccess.richardhicks.com/2025/07/08/always-on-vpn-security-updates-july-2025/

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