CVE-2022-21136: Intel Core i9-7940x Firmware DOS Flaw

CVE-2022-21136 Overview

CVE-2022-21136 is an improper input validation vulnerability affecting Intel Xeon Processors and Intel Core i9 X-series processors. The vulnerability exists in the processor firmware and may allow a privileged user with local access to potentially cause a denial of service condition. This hardware-level vulnerability is particularly concerning for enterprise and data center environments where Intel Xeon processors are widely deployed for critical workloads.

Critical Impact

A privileged attacker with local access could exploit this improper input validation flaw to trigger a denial of service condition, potentially disrupting critical server and data center operations running on affected Intel Xeon processors.

Affected Products

• Intel Xeon Scalable Processors (Bronze, Silver, Gold, and Platinum series)
• Intel Xeon D-2100 Series Processors
• Intel Core i9-7900X Series (X-series High-End Desktop)
• Intel Xeon Platinum 8100/8200/9200 Series
• Intel Xeon Gold 5100/5200/6100/6200 Series
• Intel Xeon Silver 4100/4200 Series
• Intel Xeon Bronze 3100/3200 Series

Discovery Timeline

• May 12, 2022 - CVE-2022-21136 published to NVD
• May 5, 2025 - Last updated in NVD database

Technical Details for CVE-2022-21136

Vulnerability Analysis

This vulnerability stems from improper input validation within the firmware of affected Intel processors. The flaw allows a privileged user with local access to the system to provide specially crafted input that is not properly validated by the processor firmware. When exploited, this can lead to a denial of service condition that impacts system availability.

The attack requires local access and elevated privileges, meaning an attacker would first need to establish a foothold on the target system with administrative or privileged user capabilities. While this limits the attack surface compared to remote vulnerabilities, the potential impact on enterprise server environments and data centers where these processors are commonly deployed makes this a significant concern.

The vulnerability affects a wide range of Intel Xeon Scalable processors across multiple generations, including the Skylake-SP and Cascade Lake-SP microarchitectures used extensively in cloud infrastructure and enterprise deployments.

Root Cause

The root cause is classified as CWE-20: Improper Input Validation. The processor firmware fails to adequately validate certain inputs, which can be exploited to trigger unexpected behavior. Specifically, the firmware does not perform sufficient boundary checking or validation on input data processed during certain operations, allowing malformed or out-of-specification data to cause system instability.

Attack Vector

The attack vector is local, requiring the attacker to have privileged access to the affected system. The exploitation scenario involves:

1. Attacker gains local privileged access to a system running an affected Intel Xeon or Core i9-X processor
2. Attacker provides specially crafted input that bypasses firmware validation checks
3. The improper handling of this input leads to a denial of service condition
4. System availability is impacted, potentially causing service disruption

Due to the hardware/firmware nature of this vulnerability, exploitation does not require user interaction once the attacker has local privileged access. The denial of service condition impacts system availability but does not result in confidentiality or integrity breaches according to the vulnerability assessment.

Detection Methods for CVE-2022-21136

Indicators of Compromise

• Unexpected system crashes or reboots on servers running affected Intel Xeon processors
• Kernel panic events or blue screen of death (BSOD) errors with unusual processor-related error codes
• Anomalous privileged user activity attempting to interact with low-level system components or firmware interfaces
• Unusual system call patterns from privileged processes targeting processor-specific functionality

Detection Strategies

• Monitor system event logs for unexpected processor exceptions, machine check errors (MCE), or firmware-related crashes
• Implement behavioral analysis for privileged user accounts to detect unusual activity targeting hardware interfaces
• Deploy endpoint detection solutions capable of monitoring low-level system interactions and firmware access patterns
• Establish baseline metrics for system stability and alert on deviations that may indicate exploitation attempts

Monitoring Recommendations

• Configure hardware monitoring tools to track processor health metrics and machine check exceptions
• Implement centralized logging for all privileged account activity on systems running affected processors
• Enable audit logging for BIOS/UEFI configuration changes and firmware update operations
• Monitor for unauthorized tools or processes attempting to interact with processor management interfaces

How to Mitigate CVE-2022-21136

Immediate Actions Required

• Review the Intel Security Advisory SA-00616 for specific guidance on affected processor models
• Inventory all systems containing affected Intel Xeon and Core i9-X series processors in your environment
• Apply firmware updates provided by Intel or system manufacturers as they become available
• Restrict and audit privileged local access to critical systems running affected processors
• Implement network segmentation to limit lateral movement that could enable attackers to gain local access

Patch Information

Intel has released updated firmware to address this vulnerability. Organizations should obtain firmware updates through their system manufacturer or directly from Intel. The specific remediation steps vary by processor model and system configuration.

For detailed patch information and affected processor lists, refer to the Intel Security Advisory SA-00616. System manufacturers such as Dell, HP, Lenovo, and others may provide platform-specific BIOS/firmware updates that incorporate the Intel fixes.

Workarounds

• Implement strict access controls to limit which users have privileged local access to systems with affected processors
• Apply the principle of least privilege to reduce the number of accounts capable of exploiting this vulnerability
• Enhance monitoring and alerting for privileged account activity on critical systems
• Consider isolating high-value systems until firmware updates can be applied
• Implement host-based intrusion detection to identify potential exploitation attempts

# Example: Check Intel processor model on Linux systems
cat /proc/cpuinfo | grep -E "model name|cpu family" | head -2

# Verify current BIOS/firmware version
dmidecode -t bios | grep -E "Vendor|Version|Release"

# Check for machine check exceptions in kernel logs
dmesg | grep -i "mce\|machine check"