CVE-2020-1133: Microsoft Visual Studio Privilege Escalation

CVE-2020-1133 Overview

An elevation of privilege vulnerability exists when the Diagnostics Hub Standard Collector improperly handles file operations. An attacker who successfully exploited this vulnerability could run processes in an elevated context, potentially gaining full control over the affected system.

An attacker could exploit this vulnerability by running a specially crafted application on the victim system. This local attack vector requires the attacker to already have some level of access to the target machine, but upon successful exploitation, they can escalate their privileges significantly.

Critical Impact

Successful exploitation allows attackers to elevate privileges and execute processes with elevated context, potentially leading to complete system compromise on affected Windows and Visual Studio installations.

Affected Products

• Microsoft Visual Studio 2015 Update 3
• Microsoft Visual Studio 2017
• Microsoft Visual Studio 2019
• Microsoft Windows 10 (multiple versions: 1607, 1709, 1803, 1809, 1903, 1909, 2004)
• Microsoft Windows Server 2016 (including versions 1903, 1909, 2004)
• Microsoft Windows Server 2019

Discovery Timeline

• 2020-09-11 - CVE-2020-1133 published to NVD
• 2026-02-23 - Last updated in NVD database

Technical Details for CVE-2020-1133

Vulnerability Analysis

This vulnerability resides in the Diagnostics Hub Standard Collector, a Windows component used by Visual Studio and the Windows operating system for diagnostic data collection. The flaw stems from improper handling of file operations, which creates an opportunity for privilege escalation.

The Diagnostics Hub Standard Collector service runs with elevated privileges to perform system diagnostics. When this service improperly handles certain file operations, an attacker with local access can manipulate this behavior to execute arbitrary processes in an elevated context. This type of vulnerability is particularly concerning because it allows a low-privileged user or malicious application to gain higher privileges on the system.

The attack requires local access to the victim system, meaning the attacker must first establish a foothold through other means such as phishing, social engineering, or exploiting another vulnerability. Once local access is obtained, the attacker can deploy a specially crafted application designed to trigger the improper file operation handling in the Diagnostics Hub Standard Collector.

Root Cause

The root cause of CVE-2020-1133 is improper handling of file operations within the Diagnostics Hub Standard Collector service. The service fails to properly validate or sanitize file operation requests, allowing an attacker to manipulate these operations in a way that results in code execution with elevated privileges.

This type of vulnerability typically occurs when a privileged service performs file operations on behalf of or in response to requests from lower-privileged processes without adequately verifying the legitimacy or safety of those operations.

Attack Vector

The attack vector for CVE-2020-1133 is local, requiring the attacker to execute a specially crafted application on the target system. The attack flow typically involves:

1. Attacker gains initial access to the target system with low privileges
2. Attacker deploys a malicious application designed to interact with the Diagnostics Hub Standard Collector
3. The malicious application triggers the improper file operation handling
4. The vulnerability is exploited to execute processes in an elevated context
5. Attacker gains higher privileges on the system

Since no verified code examples are available for this vulnerability, technical details about the specific exploitation mechanism can be found in the Microsoft Security Advisory for CVE-2020-1133.

Detection Methods for CVE-2020-1133

Indicators of Compromise

• Unusual process execution patterns originating from or interacting with the Diagnostics Hub Standard Collector service (DiagnosticsHub.StandardCollector.Service.exe)
• Suspicious file operations in directories associated with the Diagnostics Hub
• Unexpected privilege escalation events involving the StandardCollector service
• New or modified files in system diagnostic collection directories with anomalous timestamps

Detection Strategies

• Monitor for unusual child processes spawned by DiagnosticsHub.StandardCollector.Service.exe
• Implement application whitelisting to detect unauthorized applications attempting to interact with diagnostic services
• Use endpoint detection and response (EDR) solutions like SentinelOne to identify privilege escalation attempts
• Configure Windows Event Logging to capture detailed process creation events (Event ID 4688) with command line auditing enabled

Monitoring Recommendations

• Enable enhanced auditing for file system access on diagnostic-related directories
• Monitor Windows Security Event logs for privilege escalation indicators
• Deploy behavioral analysis tools to detect anomalous process hierarchy patterns
• Implement real-time monitoring of service interactions with the Diagnostics Hub Standard Collector

How to Mitigate CVE-2020-1133

Immediate Actions Required

• Apply the September 2020 security updates from Microsoft immediately
• Review systems for signs of exploitation or unauthorized privilege escalation
• Ensure all affected products (Visual Studio and Windows) are updated to patched versions
• Restrict local access to systems where possible to reduce the attack surface

Patch Information

Microsoft has released security updates to address this vulnerability. The update corrects the way the Diagnostics Hub Standard Collector handles file operations. Organizations should apply the appropriate patches based on their installed products:

• For Microsoft Visual Studio installations, update to the latest patched version through the Visual Studio Installer or by downloading updates directly from Microsoft
• For Windows 10 and Windows Server systems, apply the September 2020 cumulative updates via Windows Update, WSUS, or manual download from the Microsoft Update Catalog

For detailed patch information and download links, refer to the Microsoft Security Advisory for CVE-2020-1133.

Workarounds

• Restrict local access to affected systems to trusted users only
• Implement the principle of least privilege to minimize the impact of potential exploitation
• Consider temporarily disabling the Diagnostics Hub Standard Collector service if not required for operations (note: this may impact diagnostic functionality)
• Use application control solutions to prevent unauthorized applications from executing

# Example: Disable Diagnostics Hub Standard Collector service (temporary workaround)
# Note: This may impact diagnostic functionality in Visual Studio
sc config "DiagTrack" start= disabled
sc stop "DiagTrack"

# Re-enable after patching
sc config "DiagTrack" start= auto
sc start "DiagTrack"