CVE-2022-31640: HP Elite Dragonfly Firmware RCE Vulnerability

CVE-2022-31640 Overview

CVE-2022-31640 is a Time-of-Check Time-of-Use (TOCTOU) race condition vulnerability affecting the system BIOS of numerous HP PC products. This firmware-level vulnerability can potentially allow attackers to achieve arbitrary code execution, escalation of privilege, denial of service, and information disclosure on affected systems.

The vulnerability exists within the BIOS firmware layer, which operates at a highly privileged level below the operating system. Successful exploitation could enable attackers to establish persistent footholds that survive operating system reinstallation and potentially bypass security controls that depend on firmware integrity.

Critical Impact

This BIOS-level vulnerability affects hundreds of HP business and consumer PC models across EliteBook, ProBook, ZBook, Elite, ProDesk, EliteDesk, and Z-series product lines, potentially enabling persistent malware installation and privilege escalation that operates below OS-level security controls.

Affected Products

• HP EliteBook series (630-865 G4-G9, x360 variants, Healthcare Editions)
• HP ProBook series (430-655 G3-G9, x360 variants, Fortis editions)
• HP ZBook series (14u-17 G4-G9, Firefly, Fury, Power, Studio, Create variants)
• HP Elite Dragonfly series (original, G2, G3, Max)
• HP Elite x2 series (1012 G2, 1013 G3, G4, G8)
• HP Elite x360 series (830 G9, 1040 G9)
• HP EliteDesk series (705 G4-G5, 800 G3-G8, 805 G6-G8, 880 G3-G8)
• HP ProDesk series (400 G3-G7, 405 G4-G8, 480 G4-G7, 600 G3-G6, 680 G3-G6)
• HP Z Workstation series (Z1, Z2 Mini/Tower/SFF, Z238, Z240)
• HP Thin Clients (MT21-MT46, Pro MT440 G3)
• HP Retail Systems (Engage Flex/Go/One, MP9 G4, RP9 G1)
• HP ProOne and EliteOne All-in-One series

Discovery Timeline

• June 14, 2023 - CVE-2022-31640 published to NVD
• December 30, 2024 - Last updated in NVD database

Technical Details for CVE-2022-31640

Vulnerability Analysis

CVE-2022-31640 represents a Time-of-Check Time-of-Use (TOCTOU) race condition vulnerability in HP PC system BIOS firmware. This class of vulnerability (CWE-367) occurs when there is a timing gap between when a security check is performed and when the checked resource is actually used, allowing an attacker to modify the resource in that window.

In the context of BIOS firmware, TOCTOU vulnerabilities are particularly dangerous because they can allow manipulation of data structures or code after security validation has completed but before the validated content is consumed. This creates opportunities for attackers to inject malicious code or modify system configuration at the most privileged execution level.

The vulnerability requires local access to exploit, meaning an attacker must have some level of existing access to the system. However, the potential impact is severe—successful exploitation can lead to arbitrary code execution in the System Management Mode (SMM) or other privileged BIOS contexts, which operate with higher privileges than the operating system kernel itself.

Root Cause

The root cause of this vulnerability is a race condition in the BIOS firmware where the time between validating input and using that input creates an exploitable window. Specifically, the BIOS performs a security check on certain data or parameters, but there exists a window of opportunity where an attacker can modify the checked data before it is actually utilized by the firmware.

This type of vulnerability typically occurs when:

• Shared memory regions are accessible by both the BIOS/SMM and less privileged code
• Security validation and resource consumption are not performed atomically
• Insufficient synchronization mechanisms protect critical operations

The CWE-367 classification indicates that the firmware fails to properly handle concurrent access to shared resources, allowing race conditions that can be exploited for privilege escalation.

Attack Vector

Exploitation of CVE-2022-31640 requires local access to the affected system. The attack scenario involves:

1. An attacker with local system access identifies the timing window between the BIOS security check and the use of validated data
2. The attacker prepares malicious data to replace the legitimate validated content
3. Using precise timing, the attacker modifies the target memory or data structures after validation but before use
4. The BIOS then processes the malicious data with the privileges of the firmware environment

Since the attack requires local access with low privileges and no user interaction, an attacker who has gained initial access to a system through other means could leverage this vulnerability to escalate privileges to the firmware level, establishing persistence that survives OS reinstallation.

The exploitation complexity is high due to the precise timing requirements inherent in race condition attacks. However, the potential consequences—arbitrary code execution, privilege escalation, denial of service, and information disclosure at the firmware level—make this a significant concern for enterprise environments.

Detection Methods for CVE-2022-31640

Indicators of Compromise

• Unexpected BIOS firmware modifications or version changes not associated with authorized updates
• Anomalous System Management Interrupt (SMI) activity or timing patterns
• Unusual memory access patterns in regions shared between runtime and SMM environments
• BIOS integrity check failures using platform firmware verification tools

Detection Strategies

• Deploy hardware-based firmware integrity monitoring solutions that can detect unauthorized BIOS modifications
• Implement HP Sure Start or similar firmware security technologies that provide self-healing BIOS capabilities
• Use SentinelOne Singularity platform for endpoint protection with behavioral analysis to detect privilege escalation attempts
• Monitor for suspicious local privilege escalation patterns that may indicate firmware-level exploitation attempts

Monitoring Recommendations

• Enable detailed logging for firmware update events and BIOS configuration changes
• Implement Trusted Platform Module (TPM) attestation to verify firmware integrity during boot
• Configure alerts for any unauthorized attempts to access or modify BIOS settings
• Establish baseline firmware configurations and monitor for deviations across the enterprise fleet

How to Mitigate CVE-2022-31640

Immediate Actions Required

• Inventory all HP PC products in your environment to identify systems running affected BIOS firmware versions
• Prioritize patching for systems with sensitive data or elevated network privileges
• Enable BIOS password protection to prevent unauthorized firmware modifications
• Restrict local administrator access on affected systems until patches can be applied

Patch Information

HP has released BIOS updates to address CVE-2022-31640 across the extensive list of affected products. Organizations should consult the HP Security Bulletin HPSBHF03805 for specific firmware versions and download links for each affected product model.

Due to the large number of affected products spanning multiple HP business PC product lines, administrators should:

• Reference the official HP security document for model-specific patched BIOS versions
• Use HP tools such as HP Image Assistant or HP Client Management Script Library for enterprise deployment
• Validate BIOS updates in a test environment before widespread deployment
• Maintain a rollback plan in case of compatibility issues with the updated firmware

Workarounds

• Enable HP Sure Start (if available on affected models) to provide hardware-enforced firmware integrity protection
• Implement strict physical access controls to affected systems to reduce local attack surface
• Configure BIOS/UEFI Secure Boot to help ensure only signed firmware and bootloaders execute
• Deploy endpoint detection and response solutions like SentinelOne to detect and block privilege escalation attempts that may precede firmware exploitation

# Example: Query HP BIOS version using PowerShell
Get-WmiObject -Class Win32_BIOS | Select-Object SMBIOSBIOSVersion, ReleaseDate, Manufacturer

# Example: Check if Secure Boot is enabled
Confirm-SecureBootUEFI

# Use HP BIOS Configuration Utility to enable security features
# BIOSConfigUtility64.exe /setvalue:"Setup Password","YourSecurePassword"
# BIOSConfigUtility64.exe /setvalue:"TPM Device","Available"