CVE-2020-1250 in Windows
Summary
by MITRE
<p>An information disclosure vulnerability exists when the win32k component improperly provides kernel information. An attacker who successfully exploited the vulnerability could obtain information to further compromise the user’s system.</p> <p>To exploit this vulnerability, an attacker would have to log on to an affected system and run a specially crafted application.</p> <p>The security update addresses the vulnerability by correcting how win32k handles objects in memory.</p>
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Analysis
by VulDB Data Team • 02/24/2026
The vulnerability described in CVE-2020-1250 represents a critical information disclosure flaw within the Windows kernel subsystem, specifically within the win32k.sys component that manages user-mode graphics rendering and windowing operations. This component serves as a crucial bridge between user applications and the kernel, handling graphics operations, window management, and input processing for the Windows graphical user interface. The flaw arises from improper handling of kernel memory objects, creating an avenue for unauthorized information leakage that could enable attackers to extract sensitive kernel data structures and memory contents. This type of vulnerability falls under the CWE-200 category for "Information Exposure" and represents a classic example of a kernel-level information disclosure that can serve as a foundation for more sophisticated attacks.
The exploitation of this vulnerability requires local system access, meaning an attacker must first establish a foothold on the target system through legitimate user authentication or other attack vectors. Once authenticated, the attacker can execute a specially crafted application that leverages the flawed win32k.sys behavior to probe kernel memory spaces and extract information that would normally be protected from user-mode access. The vulnerability stems from inadequate validation and handling of object references within the graphics subsystem, allowing malicious code to potentially read kernel memory locations that contain sensitive data such as security credentials, system pointers, or other confidential information. This exploitation technique aligns with ATT&CK tactics involving privilege escalation and credential access, where initial access leads to information gathering that can be used for further compromise.
The operational impact of CVE-2020-1250 extends beyond simple information leakage, as the extracted kernel information can significantly aid attackers in developing more advanced exploitation techniques. The leaked kernel data could reveal memory layout details, security mechanisms, or internal system structures that would otherwise remain hidden, making subsequent attacks more effective and harder to detect. Attackers can use this information to bypass security features, predict memory locations, or craft more precise exploits targeting other system components. The vulnerability particularly affects Windows operating systems where the win32k.sys driver is present, including various versions of Windows 10, Windows Server 2016, and Windows Server 2019, making it a widespread concern across enterprise environments. Organizations running these systems face elevated risk of privilege escalation attacks and advanced persistent threats that could leverage this information disclosure for long-term system compromise.
Microsoft addressed this vulnerability through a security update that modifies the win32k.sys component's object handling mechanisms to properly validate and sanitize memory access operations. The fix ensures that kernel objects are properly managed and that unauthorized memory reads are prevented, effectively closing the information disclosure channel. System administrators should prioritize applying this update across all affected Windows systems, particularly those with high-value assets or critical infrastructure components. The mitigation strategy aligns with standard security practices for kernel-level vulnerabilities, emphasizing the importance of timely patch management and maintaining updated security controls. Organizations should also implement monitoring for suspicious process behavior and unauthorized memory access patterns that could indicate exploitation attempts. Additional defensive measures include restricting user privileges, implementing application whitelisting, and maintaining comprehensive system logging to detect potential exploitation activities that could leverage this vulnerability for further compromise.