CVE-2020-0822: Windows 10 Privilege Escalation Vulnerability

CVE-2020-0822 Overview

CVE-2020-0822 is an elevation of privilege vulnerability in the Windows Language Pack Installer. The flaw stems from improper handling of file operations by the installer component. A locally authenticated attacker can abuse the issue to execute arbitrary code with elevated privileges on the affected host. Microsoft addressed the vulnerability in its March 2020 security update cycle. The issue affects a broad range of Windows client and server releases, including Windows 7, Windows 8.1, Windows 10, and Windows Server 2008 through 2019.

Critical Impact
A low-privileged local user can escalate to elevated privileges by exploiting unsafe file operations in the Windows Language Pack Installer, resulting in full confidentiality, integrity, and availability compromise of the host.

Affected Products

Microsoft Windows 10 (versions 1607, 1709, 1803, 1809, 1903, 1909)
Microsoft Windows 7 SP1, Windows 8.1, and Windows RT 8.1
Microsoft Windows Server 2008 SP2, 2008 R2 SP1, 2012, 2012 R2, 2016, and 2019

Discovery Timeline

2020-03-12 - CVE-2020-0822 published to NVD
2024-11-21 - Last updated in NVD database

Technical Details for CVE-2020-0822

Vulnerability Analysis

The Windows Language Pack Installer performs file operations on behalf of users when adding or modifying display language packs. The installer does not adequately validate file paths or operation targets during these actions. An attacker with local access and a low-privileged account can manipulate these operations to influence files outside the installer's intended scope. The result is local privilege escalation on the affected Windows system. The vulnerability requires no user interaction beyond the attacker's own session.

Root Cause

The root cause is improper handling of file operations by the Language Pack Installer component. The installer fails to validate or sanitize file targets sufficiently when executing privileged file actions. This class of flaw typically allows redirection of file writes, deletions, or replacements to attacker-chosen locations. Microsoft classified the issue as an elevation of privilege weakness. The NVD assigns CWE category NVD-CWE-noinfo to this entry due to limited public technical detail.

Attack Vector

Exploitation requires local access to the target system and an authenticated low-privileged user context. The attacker triggers the vulnerable file operation logic in the Language Pack Installer to perform actions in a privileged context. Successful exploitation grants the attacker elevated privileges, enabling installation of programs, data tampering, and creation of new accounts with full rights. No public proof-of-concept code is available in exploit databases, and the issue is not listed in the CISA Known Exploited Vulnerabilities catalog. The vulnerability cannot be triggered remotely without an initial local foothold.

No verified public exploit code is available. Refer to the Microsoft Security Advisory CVE-2020-0822 for vendor technical details.

Detection Methods for CVE-2020-0822

Indicators of Compromise

Unexpected file creation, replacement, or deletion in system directories such as C:\Windows\System32 initiated by Language Pack Installer processes
Unusual child processes spawned from lpksetup.exe or related language pack components running with SYSTEM privileges
New local administrator accounts or scheduled tasks created shortly after Language Pack Installer activity by non-administrative users

Detection Strategies

Monitor process creation events (Windows Event ID 4688, Sysmon Event ID 1) for lpksetup.exe invocations triggered by standard user accounts
Audit file system access (Sysmon Event ID 11) for writes to protected system paths originating from language pack installer activity
Correlate token elevation events (Windows Event ID 4672) with prior language pack installer execution to identify potential privilege escalation chains

Monitoring Recommendations

Enable command-line process auditing and Sysmon across Windows endpoints to capture installer execution context and parent-child process relationships
Alert on privilege escalation patterns where a low-privileged user session is followed by SYSTEM-level file modifications in protected directories
Maintain centralized log collection in a SIEM to retain installer telemetry for incident response and threat hunting

How to Mitigate CVE-2020-0822

Immediate Actions Required

Apply the March 2020 Microsoft security updates that address CVE-2020-0822 to all affected Windows client and server systems
Inventory all Windows hosts running Windows 7 SP1, 8.1, 10, and Server 2008 through 2019 to confirm patch deployment status
Restrict interactive logon rights on sensitive systems to limit the population of users who can attempt local privilege escalation

Patch Information

Microsoft released security updates for all affected Windows versions on March 10, 2020. Administrators should consult the Microsoft Security Advisory CVE-2020-0822 to identify the specific KB article for each Windows release and deploy through Windows Update, WSUS, or Microsoft Endpoint Configuration Manager.

Workarounds

No official vendor workaround is documented; patching is the supported remediation path
Reduce attack surface by removing unnecessary local user accounts and enforcing the principle of least privilege on workstations and servers
Restrict the ability of standard users to launch language pack installation workflows on managed endpoints via application control policies such as Windows Defender Application Control or AppLocker

bash

# Verify installed updates on a Windows host
wmic qfe list brief /format:table

# Trigger Windows Update scan and install
UsoClient StartScan
UsoClient StartDownload
UsoClient StartInstall