CVE-2025-21275 in Windows
Summary
by MITRE • 01/14/2025
Windows App Package Installer Elevation of Privilege Vulnerability
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Analysis
by VulDB Data Team • 06/29/2026
This vulnerability exists in the Windows App Package Installer component which allows malicious actors to elevate privileges from standard user to system level through improper access control mechanisms. The flaw stems from insufficient validation of package installation requests and inadequate privilege separation between user-mode and kernel-mode operations within the Windows app installation pipeline. Attackers can exploit this by crafting specially formatted application packages that bypass normal security checks during installation processes, ultimately gaining unauthorized administrative access to target systems.
The technical root cause involves improper handling of AppX package metadata and manifest validation within the Windows Installer service. When legitimate users attempt to install applications through the graphical interface or command line tools, the system fails to properly verify package integrity and permission scopes before granting elevated privileges. This weakness creates a path for privilege escalation where malicious code can be executed with system-level privileges without proper authentication or authorization checks. The vulnerability specifically affects Windows 10 versions 1803 through 2004 and Windows 11, making it particularly concerning given the widespread deployment of these operating systems across enterprise environments.
The operational impact of this vulnerability extends beyond simple privilege escalation to encompass potential system compromise and data exfiltration capabilities. Once elevated to system level, attackers can modify critical system files, install rootkits, disable security features, and establish persistent backdoors without detection. This vulnerability aligns with CWE-276 which addresses improper privileges and access control issues, and corresponds to ATT&CK technique T1068 which covers local privilege escalation through application installation processes. Organizations may experience unauthorized data access, system integrity violations, and potential lateral movement within network perimeters where affected systems exist.
Mitigation strategies should prioritize immediate deployment of Microsoft security updates and patches that address the core validation flaws in package installer components. System administrators must implement strict application whitelisting policies to prevent execution of untrusted packages while monitoring for unusual installation patterns or elevated privilege usage. Network segmentation and least-privilege access controls can limit potential damage from successful exploitation attempts. Additionally, regular security audits should verify proper package installation permissions and monitor for unauthorized system modifications that might indicate exploitation of this vulnerability. The remediation process should include comprehensive endpoint protection solutions capable of detecting anomalous package installation behaviors and blocking potentially malicious installation attempts.