CVE-2020-17045 in Windows
Summary
by MITRE • 11/11/2020
Windows KernelStream Information Disclosure Vulnerability
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Analysis
by VulDB Data Team • 12/05/2020
The Windows KernelStream Information Disclosure Vulnerability identified as CVE-2020-17045 represents a critical security flaw within the Windows kernel that allows unauthorized information disclosure through improper handling of kernel stream objects. This vulnerability resides in the kernel-mode components responsible for managing stream operations and can be exploited by malicious actors to gain access to sensitive kernel memory structures and data. The flaw specifically affects the Windows kernel's handling of stream information, creating potential pathways for attackers to extract confidential system information that should remain protected within kernel space. The vulnerability was discovered in the Windows operating system's kernel streaming subsystem and impacts multiple Windows versions including Windows 10, Windows Server 2016, and Windows Server 2019.
The technical implementation of this vulnerability stems from inadequate validation and access control mechanisms within the kernel stream processing code. When applications or processes interact with kernel stream objects, the system fails to properly enforce memory boundaries and access restrictions, allowing for potential information leakage. This issue manifests when kernel stream objects are improperly managed during operations that involve data transfer between user and kernel space, creating opportunities for attackers to craft malicious requests that can trigger information disclosure behaviors. The vulnerability is classified under CWE-200, which specifically addresses "Information Exposure" and represents a fundamental breakdown in the principle of least privilege within kernel-mode operations. The flaw allows for potential exploitation through crafted kernel stream operations that can cause the system to leak memory contents, including potentially sensitive data structures, kernel pointers, and other confidential information that should remain isolated from user-space processes.
The operational impact of CVE-2020-17045 extends beyond simple information disclosure, as the leaked kernel information can provide attackers with critical insights into system memory layout and kernel structures. This information can be leveraged for more sophisticated attacks including privilege escalation, kernel exploitation, and advanced persistent threat operations. The vulnerability can be particularly dangerous when combined with other exploits, as the leaked information can aid in bypassing security mechanisms like address space layout randomization and kernel address space protection. Attackers can potentially use the disclosed information to craft more effective exploits that target specific kernel memory regions, making this vulnerability a significant concern for enterprise environments and systems handling sensitive data. The impact is especially severe in environments where Windows systems are exposed to untrusted network traffic or where privilege escalation opportunities exist, as the information disclosure can provide attackers with the necessary details to develop more targeted and effective attack vectors.
Mitigation strategies for CVE-2020-17045 should focus on immediate patch deployment through Microsoft's regular security updates, which address the underlying kernel stream handling code. Organizations should implement comprehensive monitoring of kernel stream operations and establish baseline behaviors to detect anomalous activities that might indicate exploitation attempts. Network segmentation and access control measures can help limit the potential impact of exploitation by reducing attack surface and preventing lateral movement. Additionally, implementing kernel-mode exploit protection mechanisms and maintaining updated security tooling can provide additional layers of defense. The vulnerability aligns with ATT&CK technique T1068, which covers "Exploitation for Privilege Escalation," and T1005, which covers "Data from Local System," demonstrating how information disclosure can enable more comprehensive attack operations. System administrators should also consider implementing memory protection mechanisms and ensuring that all Windows systems are updated with the latest security patches to prevent exploitation attempts that rely on this information disclosure vulnerability.