CVE-2020-1405 in Windows
Summary
by MITRE
An elevation of privilege vulnerability exists when Windows Mobile Device Management (MDM) Diagnostics improperly handles junctions, aka 'Windows Mobile Device Management Diagnostics Elevation of Privilege Vulnerability'. This CVE ID is unique from CVE-2020-1372.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 10/29/2020
The vulnerability described in CVE-2020-1405 represents a critical elevation of privilege flaw within Windows Mobile Device Management Diagnostics functionality. This issue specifically manifests when the MDM diagnostics component processes symbolic links or junction points in an insecure manner, allowing attackers to escalate their privileges from standard user level to SYSTEM level access. The vulnerability affects Windows operating systems that implement mobile device management capabilities, particularly those with MDM diagnostics features enabled. Security researchers identified this weakness through careful analysis of how the diagnostic subsystem handles file system junctions, which are essentially directory links that point to other directories in the file system structure.
The technical flaw stems from improper validation and handling of junction points within the Windows MDM diagnostics framework. When the system processes diagnostic requests, it fails to adequately sanitize or validate junction paths, potentially allowing malicious actors to manipulate the diagnostic process to access restricted system resources. This vulnerability operates under CWE-78, which addresses improper neutralization of special elements used in OS commands, and more specifically relates to CWE-22, which covers improper limitation of a pathname to a restricted directory. The flaw enables attackers to traverse file system boundaries through junction manipulation, effectively bypassing normal access controls and privilege boundaries.
The operational impact of this vulnerability is severe as it allows attackers to achieve SYSTEM-level privileges without requiring administrative credentials or elevated access rights. Once exploited, an attacker could gain complete control over the affected system, including the ability to install malware, modify system files, access sensitive data, and potentially establish persistent backdoors. The vulnerability is particularly dangerous in enterprise environments where MDM solutions are widely deployed, as it could enable attackers to compromise multiple devices simultaneously. The attack surface extends beyond individual devices to potentially affect entire device management infrastructures, making this a significant concern for organizations relying on Windows MDM solutions for mobile device management.
Mitigation strategies should focus on immediate patch deployment through Microsoft's security updates, which address the specific junction handling logic in the MDM diagnostics component. Organizations should also implement network segmentation to limit access to MDM management interfaces and enforce strict access controls for diagnostic functions. The ATT&CK framework categorizes this vulnerability under T1068, which covers 'Exploitation for Privilege Escalation', and T1566, which covers 'Phishing', as attackers may use social engineering to gain initial access before exploiting this privilege escalation vector. Additional defensive measures include monitoring for unusual junction creation patterns, implementing application whitelisting policies, and conducting regular security assessments of MDM configurations to identify and remediate similar vulnerabilities in the system architecture.