CVE-2020-1465: Microsoft OneDrive Privilege Escalation

CVE-2020-1465 Overview

An elevation of privilege vulnerability exists in Microsoft OneDrive that allows file deletion in arbitrary locations. To exploit the vulnerability, an attacker would first have to log on to the system. This vulnerability is also known as 'Microsoft OneDrive Elevation of Privilege Vulnerability' and affects the OneDrive client for Windows systems.

Critical Impact

Local attackers with low privileges can exploit this vulnerability to delete files in arbitrary locations on the system, potentially leading to denial of service conditions, system instability, or security control bypass by removing critical files.

Affected Products

• Microsoft OneDrive for Windows

Discovery Timeline

• July 14, 2020 - CVE-2020-1465 published to NVD
• November 21, 2024 - Last updated in NVD database

Technical Details for CVE-2020-1465

Vulnerability Analysis

This elevation of privilege vulnerability in Microsoft OneDrive allows authenticated local attackers to delete files in arbitrary locations on the affected system. The vulnerability requires the attacker to have local access and the ability to log on to the system, but does not require any user interaction to exploit.

The attack can be executed from a local context with low privilege requirements. If successfully exploited, the attacker can impact the confidentiality, integrity, and availability of the system by manipulating file system objects outside their normal privilege boundaries.

Root Cause

The root cause of this vulnerability stems from improper privilege handling within the Microsoft OneDrive application on Windows. The OneDrive client fails to properly validate or restrict file deletion operations, allowing a low-privileged user to leverage OneDrive's elevated permissions to delete files in locations they would not normally have access to modify.

Attack Vector

The exploitation of CVE-2020-1465 requires local access to the target system. An attacker must first authenticate to the system with valid credentials. Once logged in, the attacker can manipulate the OneDrive client or its associated processes to perform file deletion operations with elevated privileges.

The attack flow typically involves:

1. Authenticating to the target Windows system with low-privilege credentials
2. Identifying the OneDrive installation and associated processes
3. Leveraging the privilege escalation flaw to delete files in protected locations
4. Targeting critical system files, security controls, or other protected resources

This type of arbitrary file deletion can be weaponized to disable security software, remove audit logs, or cause system instability.

Detection Methods for CVE-2020-1465

Indicators of Compromise

• Unexpected file deletions in system directories or protected locations
• Anomalous OneDrive process behavior or unusual child process spawning
• File system audit events showing deletions by the OneDrive process in non-standard locations
• Missing security-critical files or system components after OneDrive activity

Detection Strategies

• Monitor file system operations performed by OneDrive-related processes (OneDrive.exe, OneDriveSetup.exe)
• Implement file integrity monitoring (FIM) on critical system directories
• Enable Windows Security Auditing for file deletion events (Event ID 4663)
• Deploy endpoint detection rules to identify privilege escalation patterns associated with cloud sync applications

Monitoring Recommendations

• Configure alerts for file deletions in %SystemRoot%, %ProgramFiles%, and other protected directories by non-administrative processes
• Monitor OneDrive process behavior for suspicious file operations outside of user sync folders
• Implement behavioral analysis to detect elevation of privilege attempts through legitimate applications
• Review Windows Event Logs for anomalous security events correlated with OneDrive activity

How to Mitigate CVE-2020-1465

Immediate Actions Required

• Update Microsoft OneDrive to the latest available version from Microsoft
• Review and audit file permissions on critical system directories
• Implement the principle of least privilege for user accounts on affected systems
• Consider temporarily restricting OneDrive functionality until patches are applied in high-security environments

Patch Information

Microsoft has released security updates to address this vulnerability. Administrators should apply the latest OneDrive updates as documented in the Microsoft Security Advisory for CVE-2020-1465. OneDrive typically updates automatically, but manual verification of the installed version is recommended to ensure protection.

Workarounds

• Restrict local logon access to trusted users only on sensitive systems
• Implement application control policies to monitor and restrict OneDrive behavior
• Deploy file system integrity monitoring to detect and alert on unauthorized file deletions
• Consider running OneDrive with reduced privileges or in a sandboxed environment if updates cannot be immediately applied

# Verify OneDrive version and check for updates
# Run in PowerShell to check installed OneDrive version
Get-ItemProperty "HKCU:\Software\Microsoft\OneDrive" | Select-Object Version

# Force OneDrive update check
& "$env:LOCALAPPDATA\Microsoft\OneDrive\OneDrive.exe" /update