CVE-2026-100218 in Windows
Summary
by MITRE • 10/13/2026
Use after free in Remote Desktop Gateway Service allows an unauthorized attacker to execute code over a network.
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Analysis
by VulDB Data Team • 10/13/2026
The vulnerability described constitutes a critical security flaw within the Microsoft Remote Desktop Gateway service, specifically manifesting as a use-after-free condition that enables remote code execution by an unauthenticated attacker. This type of memory corruption error arises when software continues to use a pointer after it has been freed from its allocated memory block, leading to undefined behavior that can be exploited for malicious purposes. In the context of network-facing services like Remote Desktop Gateway, which acts as a proxy allowing users to access internal resources via HTTPS, such flaws are particularly dangerous because they expose the underlying operating system kernel or service processes to direct exploitation over the internet without requiring prior authentication credentials.
From a technical perspective, use-after-free vulnerabilities typically occur when an application fails to properly manage memory lifecycle events, specifically failing to nullify pointers after deallocation or allowing access to freed memory regions that may be reallocated for other purposes. When an attacker crafts specific network packets targeting this flaw within the Remote Desktop Gateway service, they can manipulate the heap structure of the process. By carefully controlling the data written into the reused memory space, often through a technique known as heap spraying or precise allocation control, the attacker can overwrite critical function pointers or object vtables. This manipulation allows for arbitrary code execution with the privileges of the compromised service account, which is typically high-level administrative access on the server hosting the gateway role.
The operational impact of this vulnerability is severe, potentially leading to complete compromise of the affected system and any resources accessible through it. An attacker who successfully exploits this flaw gains full control over the Remote Desktop Gateway host, enabling them to install malware, steal sensitive data, create new user accounts for persistent access, or pivot further into the internal network infrastructure protected by the gateway. Given that Remote Desktop Gateways are often positioned at the perimeter of corporate networks as entry points for remote workers and partners, a successful exploitation effectively breaches the organization's external security boundary. This aligns with common attack patterns observed in real-world incidents where initial access is gained through vulnerable internet-facing services to establish a foothold within an enterprise environment.
This vulnerability maps directly to CWE-416, Use After Free, which categorizes errors resulting from improper memory management practices that lead to accessing freed memory regions. Furthermore, the exploitation technique falls under MITRE ATT&CK techniques related to Initial Access and Execution, specifically leveraging vulnerable services for remote code execution. Attackers often utilize such vulnerabilities in automated campaigns or targeted attacks against organizations with exposed Remote Desktop infrastructure. The lack of authentication requirement makes this a high-severity issue, as it does not rely on social engineering or credential theft but rather on the technical exploitation of memory handling errors within the service logic itself.
Mitigation strategies primarily involve applying vendor-provided security patches that address the underlying memory management issues in the Remote Desktop Gateway software. Organizations should ensure their systems are updated to the latest stable release containing these fixes as a priority action. In environments where immediate patching is not feasible, network-level controls such as firewall rules or web application firewalls can be configured to restrict access to the Remote Desktop Gateway service only from trusted IP addresses, thereby reducing the attack surface exposed to potential attackers on the public internet. Additionally, implementing strict input validation and monitoring for anomalous traffic patterns targeting the gateway service can aid in early detection of exploitation attempts before successful compromise occurs.