CVE-2020-0875 in Windows
Summary
by MITRE
<p>An information disclosure vulnerability exists in how splwow64.exe handles certain calls. An attacker who successfully exploited this vulnerability could obtain information to further compromise the user’s system (low-integrity to medium-integrity).</p> <p>This vulnerability by itself does not allow arbitrary code execution; however, it could allow arbitrary code to be run if the attacker uses it in combination with another vulnerability (such as a remote code execution vulnerability or another elevation of privilege vulnerability) that is capable of leveraging the elevated privileges when code execution is attempted.</p> <p>The security update addresses the vulnerability by ensuring splwow64.exe properly handles these calls.</p>
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Analysis
by VulDB Data Team • 02/24/2026
The vulnerability described in CVE-2020-0875 represents a critical information disclosure flaw within the Windows operating system's splwow64.exe component, which serves as a 32-bit Windows on Windows 64-bit subsystem helper process. This process facilitates communication between 32-bit and 64-bit applications, particularly during printer driver operations and other system services. The vulnerability specifically manifests when splwow64.exe improperly handles certain API calls, creating an information disclosure channel that could potentially be exploited by malicious actors. The flaw operates at the privilege level boundary between low-integrity and medium-integrity processes, making it particularly dangerous as it allows attackers to gather sensitive system information that could be leveraged for further compromise. This type of vulnerability falls under the CWE-200 category of "Information Exposure" and aligns with ATT&CK technique T1059.001 for Command and Scripting Interpreter, as it could enable attackers to gather information needed for subsequent exploitation phases.
The technical implementation of this vulnerability involves improper handling of inter-process communication mechanisms within the Windows subsystem architecture. When splwow64.exe receives specific calls that should be properly validated and sanitized, the process fails to adequately protect sensitive information from being exposed to lower privilege processes. This information disclosure occurs through memory corruption or improper access control mechanisms that allow unauthorized data retrieval. The vulnerability's impact is particularly concerning because it operates at a system level where privilege boundaries are typically well-defined and enforced. Attackers could potentially exploit this flaw to gather system configuration details, process information, or other sensitive data that would normally be restricted to higher privilege contexts. The vulnerability's design allows for a potential privilege escalation chain where the information disclosed could be used to identify system weaknesses or to craft more sophisticated attacks targeting other system components.
The operational impact of CVE-2020-0875 extends beyond simple information disclosure, as it creates a foundation for more severe security breaches when combined with other vulnerabilities. While the flaw itself cannot execute arbitrary code directly, it serves as a critical stepping stone in attack scenarios where attackers seek to elevate privileges or gain deeper system access. The vulnerability's potential for exploitation becomes particularly dangerous when paired with remote code execution vulnerabilities or other privilege escalation flaws, as the disclosed information could provide attackers with the knowledge needed to successfully compromise system integrity. This type of vulnerability represents a classic example of how information disclosure flaws can be weaponized in advanced persistent threat campaigns, where attackers systematically gather intelligence before launching more destructive attacks. The medium-integrity access level provided by this vulnerability means that attackers could potentially leverage it from various attack vectors including web-based attacks or social engineering campaigns that result in users executing malicious code with low privileges.
Mitigation strategies for CVE-2020-0875 should focus on both immediate patch application and broader system hardening measures. Microsoft released a security update that properly addresses the handling of API calls within splwow64.exe, ensuring that information disclosure scenarios are properly prevented through improved validation and access control mechanisms. Organizations should prioritize immediate deployment of this security update across all affected systems, particularly those running Windows 10 and Windows Server 2016 environments where the vulnerability is most prevalent. Beyond patching, system administrators should implement additional monitoring controls to detect unusual API call patterns or information disclosure attempts that might indicate exploitation attempts. Network segmentation and privilege separation measures can help limit the potential impact of successful exploitation attempts, while comprehensive logging of splwow64.exe activities can aid in forensic analysis if the vulnerability is successfully targeted. The vulnerability's nature aligns with ATT&CK technique T1068 for Exploitation for Privilege Escalation, emphasizing the importance of layered security approaches that address both the immediate vulnerability and broader system security posture. Regular security assessments and vulnerability scanning should include checks for proper implementation of the security update to ensure complete remediation of the information disclosure vulnerability.