Description

Access of resource using incompatible type ('type confusion') in Windows DWM Core Library allows an authorized attacker to elevate privileges locally.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "7.8",
  "pubDate": "2026-08-11T17:18:16.063Z",
  "pubdate": "2026-08-11T17:18:16.063Z",
  "executiveSummary": "An elevation of privilege vulnerability exists within the Windows DWM Core Library, specifically involving an access of resource using incompatible type, commonly classified as a type confusion flaw. This security defect allows an authorized local attacker to elevate their execution privileges on targeted Windows systems. The compromise affects the core desktop composition infrastructure, which operates with elevated system privileges to manage graphical rendering and window management. The risk implication is severe, as successful exploitation enables low-privilege users to execute arbitrary code or commands with higher privileges, potentially leading to full system compromise. The primary prerequisite for exploitation is local access to the target system, coupled with prior authorization or the ability to execute code locally. The attack requires the adversary to interact with the vulnerable DWM Core Library component by passing maliciously crafted inputs or manipulating object types in a manner that the underlying memory management and type checking fail to handle safely, resulting in unsafe type resolution and subsequent privilege escalation.",
  "technicalDetails": "The vulnerability stems from a type confusion flaw residing in the Windows DWM Core Library. A type confusion vulnerability occurs when an application allocates a resource of a specific type but subsequently accesses or uses that resource as if it were a different, incompatible type. In the context of the Windows DWM Core Library, this improper handling of object types arises during the processing of inter-process communications, rendering commands, or shared memory structures managed by the Desktop Window Manager. The root cause is insufficient validation and type verification checks performed by the vulnerable component when casting or referencing objects internally, allowing mismatched types to bypass safety boundaries.\nThe affected component is the Windows DWM Core Library, which is responsible for hardware-accelerated desktop composition and visual effects in the Windows operating system. Because DWM operates within a privileged context to interact with the graphics subsystem and render windows across user sessions, vulnerabilities in this library provide a strategic target for privilege escalation. The vulnerability requires local access to the system and that the attacker is already authorized to execute code within a standard user context. Network exposure is typically not applicable as the attack surface relies on local IPC mechanisms or direct interaction with the DWM API.\nThe step-by-step attack flow begins with the authenticated local attacker preparing a specially crafted payload or sequence of API calls directed at the Windows DWM Core Library. The attacker interacts with the DWM service, supplying input designed to instantiate or manipulate objects in a specific state. Due to the lack of robust type checking in the vulnerable component, the application misinterprets the underlying data structure, treating an object of type A as if it were of type B. When the DWM Core Library performs operations based on this false assumption—such as invoking function pointers or reading offset values associated with the incorrect type—memory corruption or arbitrary read and write primitives can be achieved.\nPost-exploitation impact and payload behavior center around the transition from a low-integrity or medium-integrity execution context to a higher privilege level, such as SYSTEM or an equivalent administrative context. By leveraging the type confusion to manipulate internal control flow or overwrite critical data structures within the DWM process space, the attacker can execute arbitrary code with the privileges of the DWM service. This capability allows the adversary to bypass security boundaries, install persistent backdoors, modify system files, or access sensitive data across the operating system."
}