CVE-2020-8704: Intel LMS Privilege Escalation Vulnerability

CVE-2020-8704 Overview

A race condition vulnerability exists in a subsystem of Intel Local Manageability Service (LMS) versions prior to 2039.1.0.0. This vulnerability allows a privileged user to potentially escalate privileges through local access. The flaw affects both Intel's LMS software and numerous Siemens industrial computing devices that incorporate Intel management technologies.

Critical Impact

A privileged attacker with local access can exploit this race condition to escalate privileges, potentially gaining elevated system control over affected Intel LMS installations and Siemens industrial devices.

Affected Products

• Intel Local Manageability Service (versions before 2039.1.0.0)
• Siemens SIMATIC Field PG M5 and M6 (firmware affected)
• Siemens SIMATIC IPC427E, IPC477E, IPC477E Pro
• Siemens SIMATIC IPC527G, IPC547G
• Siemens SIMATIC IPC627E, IPC647E, IPC677E, IPC847E
• Siemens SIMATIC ITP1000

Discovery Timeline

• June 9, 2021 - CVE-2020-8704 published to NVD
• November 21, 2024 - Last updated in NVD database

Technical Details for CVE-2020-8704

Vulnerability Analysis

This vulnerability is classified as CWE-362 (Concurrent Execution using Shared Resource with Improper Synchronization), commonly known as a race condition. The flaw exists within a subsystem of Intel's Local Manageability Service, which is a component used for out-of-band system management capabilities on Intel platforms.

Race conditions occur when multiple processes or threads access shared resources without proper synchronization, leading to unpredictable behavior. In this case, the improper handling of concurrent operations within the LMS subsystem creates a window where an attacker can manipulate execution flow. While the attack requires high privileges and local access, successful exploitation enables privilege escalation, which can lead to complete system compromise.

The vulnerability's impact extends beyond Intel systems to numerous Siemens industrial computing platforms that incorporate Intel management technologies, making it particularly relevant for operational technology (OT) and industrial control system (ICS) environments.

Root Cause

The root cause is improper synchronization of concurrent execution within a subsystem of Intel Local Manageability Service. The vulnerable code fails to properly lock or synchronize access to shared resources during critical operations, creating a Time-of-Check Time-of-Use (TOCTOU) window that can be exploited.

Attack Vector

This vulnerability requires local access to the target system and existing privileged user credentials. The attacker must be able to execute code locally and time their exploitation to coincide with the vulnerable race window in the LMS subsystem. The attack is considered high complexity due to the timing-dependent nature of race condition exploitation.

The exploitation involves manipulating the timing of operations to achieve an inconsistent state between when a resource is checked and when it is used, allowing the attacker to escalate their existing privileges to gain additional system access.

Detection Methods for CVE-2020-8704

Indicators of Compromise

• Unusual process behavior or unexpected privilege changes associated with Intel LMS service (LMS.exe)
• Anomalous system calls or resource access patterns from Intel management subsystem components
• Evidence of repeated execution attempts or timing-based exploitation patterns in system logs

Detection Strategies

• Monitor Intel Local Manageability Service process behavior for signs of exploitation or unusual activity
• Implement endpoint detection and response (EDR) solutions to identify privilege escalation attempts
• Use SentinelOne Singularity to detect behavioral anomalies associated with race condition exploitation patterns
• Audit local privileged account activity on systems running Intel LMS

Monitoring Recommendations

• Enable enhanced logging for Intel management services and related subsystems
• Configure alerts for unexpected privilege escalation events on affected systems
• Monitor firmware integrity on Siemens SIMATIC industrial devices
• Implement real-time behavioral analysis for local privilege escalation attempts

How to Mitigate CVE-2020-8704

Immediate Actions Required

• Update Intel Local Manageability Service to version 2039.1.0.0 or later immediately
• Apply firmware updates to all affected Siemens SIMATIC devices per vendor guidance
• Review and restrict local privileged access to systems running vulnerable LMS versions
• Implement network segmentation to limit exposure of industrial systems

Patch Information

Intel has released a patched version of the Local Manageability Service (version 2039.1.0.0 and later) that addresses this race condition vulnerability. Organizations should consult the Intel Security Advisory SA-00459 for detailed patch information and download links.

For Siemens industrial devices, refer to the Siemens Security Advisory SSA-309571 for device-specific firmware updates and mitigation guidance.

Workarounds

• Restrict local access to affected systems to only essential personnel with verified privileged accounts
• Implement strong access controls and monitor privileged account usage on systems with Intel LMS
• Consider temporarily disabling Intel LMS on systems where the service is not required for operations
• Apply network segmentation to isolate industrial control systems from general network access
• Deploy endpoint protection solutions capable of detecting behavioral anomalies associated with privilege escalation attempts

# Verify Intel LMS version on Windows systems
wmic product where "name like '%Intel%Local Management%'" get name, version

# Check service status
sc query LMS