CVE-2020-1467 in Windows
Summary
by MITRE
An elevation of privilege vulnerability exists when Windows improperly handles hard links. An attacker who successfully exploited this vulnerability could overwrite a targeted file leading to an elevated status. To exploit this vulnerability, an attacker would first have to log on to the system. An attacker could then run a specially crafted application that could exploit the vulnerability and take control of an affected system. The security update addresses the vulnerability by correcting how Windows handles hard links.
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Analysis
by VulDB Data Team • 02/23/2026
The vulnerability described in CVE-2020-1467 represents a critical elevation of privilege flaw within the Windows operating system's handling of hard links. This weakness falls under the category of improper handling of file system objects and aligns with CWE-264, which addresses permissions, privileges, and access controls. The vulnerability stems from Windows' insufficient validation mechanisms when processing hard link operations, creating a pathway for malicious actors to manipulate file system structures. Hard links are symbolic references that allow multiple directory entries to point to the same file data on disk, but Windows' inadequate implementation creates opportunities for exploitation that could fundamentally compromise system security.
The exploitation scenario for this vulnerability requires an initial foothold through user authentication, making it a post-authentication privilege escalation vector. Attackers must first establish a valid user session on the target system before executing malicious code designed to exploit the hard link handling flaw. This prerequisite aligns with the ATT&CK framework's privilege escalation tactics, specifically targeting the T1068 technique for local privilege escalation. The malicious application would leverage the vulnerability to overwrite targeted files with malicious content, potentially replacing critical system files or executables with attacker-controlled versions that would execute with elevated privileges. The exploitation process essentially allows attackers to gain SYSTEM-level access by manipulating file system metadata rather than through traditional attack vectors.
The operational impact of CVE-2020-1467 extends beyond simple privilege escalation, as it provides attackers with the capability to fundamentally compromise system integrity and availability. Once exploited, the vulnerability could enable attackers to install backdoors, modify system configurations, or corrupt critical system files that would persist across reboots. The ability to overwrite targeted files with elevated status creates a persistent threat vector that could remain undetected for extended periods. This vulnerability particularly affects systems where users have legitimate access to the file system but lack administrative privileges, making it a significant concern for enterprise environments where least privilege principles are implemented. The security update addresses this issue by modifying Windows' hard link processing mechanisms to properly validate file operations and prevent unauthorized overwrites.
Microsoft's remediation for CVE-2020-1467 involves strengthening the file system validation processes when handling hard link operations, ensuring that Windows properly checks permissions and file integrity before allowing hard link creation or modification. The fix implements additional checks that prevent attackers from exploiting the gap in hard link handling logic. Organizations should prioritize applying this update across all affected Windows systems, particularly those running server operating systems where the impact of privilege escalation could be most severe. The vulnerability demonstrates the importance of robust file system security implementations and highlights how seemingly minor flaws in system internals can create significant security risks. Security teams should monitor for exploitation attempts and ensure proper access controls are maintained to minimize the attack surface for such vulnerabilities.