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

CVE-2022-31640 Overview

CVE-2022-31640 affects the system BIOS of a wide range of HP PC products. HP disclosed potential vulnerabilities that may allow arbitrary code execution, escalation of privilege, denial of service, and information disclosure. The underlying weakness is classified as CWE-367: Time-of-check Time-of-use (TOCTOU) Race Condition, a defect class that is particularly damaging at the firmware level because successful exploitation can persist below the operating system. The flaw spans HP EliteBook, ProBook, ZBook, EliteDesk, ProDesk, EliteOne, ProOne, Z Workstation, Engage retail systems, and mobile thin client product lines.

Critical Impact
A local attacker with low privileges can win a race condition in BIOS code to achieve arbitrary code execution at the firmware layer, leading to privilege escalation, denial of service, or disclosure of sensitive system information.

Affected Products

HP EliteBook, ProBook, and ZBook notebook firmware (multiple generations including G3 through G9)
HP EliteDesk, ProDesk, EliteOne, ProOne, and Z series desktop and workstation firmware
HP Engage retail systems, mobile thin clients (mt21–mt46), and Pro MT440 G3

Discovery Timeline

2023-06-14 - CVE-2022-31640 published to NVD
2024-12-30 - Last updated in NVD database

Technical Details for CVE-2022-31640

Vulnerability Analysis

The vulnerability resides in the system BIOS of affected HP PC products and stems from a Time-of-check Time-of-use [CWE-367] race condition. In a TOCTOU defect, the BIOS validates a resource, parameter, or memory state at one point and then operates on it at a later point. An attacker who can modify the resource between the check and the use can cause the BIOS to act on attacker-controlled data while still believing it has been validated.

Because the defect lives in firmware that executes during boot and within System Management Mode (SMM) contexts, successful exploitation grants control at a privilege level higher than the operating system kernel. HP states that the impact includes arbitrary code execution, escalation of privilege, denial of service, and information disclosure. The wide product spread indicates the affected code path is shared across many platform BIOS images.

Root Cause

The root cause is an unsynchronized check-then-use sequence inside the BIOS. The firmware does not enforce atomicity between validation and consumption of the affected resource, allowing a concurrent agent to alter that resource after the validation step has completed.

Attack Vector

Exploitation requires local access and low privileges on the target host, with no user interaction. The attack complexity is high because the attacker must reliably win the race window between the BIOS performing its check and using the validated data. When the window is won, the attacker breaks out of the operating system trust boundary and gains execution inside the firmware. Refer to the HP Security Bulletin HPSBHF03805 for the authoritative impact statement.

No verified proof-of-concept code is available in public sources. The vulnerability mechanism is described in prose because no sanitized exploitation example has been released by the vendor or independent researchers.

Detection Methods for CVE-2022-31640

Indicators of Compromise

Unexpected changes to BIOS version strings, BIOS configuration, or SMBIOS data on affected HP models
UEFI variable modifications or new entries in BootOrder, Boot####, or vendor-specific NVRAM variables without an authorized administrator action
Anomalous SMM activity or unexplained system management interrupts (SMIs) recorded by platform telemetry

Detection Strategies

Inventory all HP endpoints against the affected model list in HPSBHF03805 and compare installed BIOS versions to the fixed versions published by HP
Use platform attestation, where available, to capture and baseline TPM PCR measurements for the BIOS and boot components
Monitor for local processes that load BIOS update tooling, SMI-triggering utilities, or low-level chipset access drivers outside of approved maintenance windows

Monitoring Recommendations

Centralize BIOS version and configuration telemetry from endpoint management agents and alert on drift from the patched baseline
Correlate unexpected reboots and firmware update events with user identity and change-management records to surface unsanctioned firmware activity
Track use of administrative privileges that can reach the BIOS interface, since exploitation requires local access

How to Mitigate CVE-2022-31640

Immediate Actions Required

Apply the BIOS update specified for each affected HP model as listed in HP Security Bulletin HPSBHF03805
Restrict local administrator rights on affected systems to limit which accounts can stage a local race-condition attack
Enable Secure Boot, set a BIOS administrator password, and disable unused BIOS update channels where the platform supports them

Patch Information

HP has released firmware updates that remediate CVE-2022-31640. Customers should consult HP Security Bulletin HPSBHF03805 for the minimum fixed BIOS version for each model and deploy updates through HP Image Assistant, HP Manageability Integration Kit, or the standard enterprise software distribution process.

Workarounds

No vendor-supplied workaround replaces the BIOS update; treat firmware patching as the primary control
Enforce least privilege so that only vetted administrators can execute code locally on impacted endpoints
Require physical and remote access controls, including full-disk encryption and pre-boot authentication, to raise the cost of local exploitation prior to patch deployment

bash

# Verify installed BIOS version on Windows endpoints
wmic bios get smbiosbiosversion,manufacturer,releasedate

# PowerShell alternative for fleet collection
Get-CimInstance -ClassName Win32_BIOS | Select-Object Manufacturer, SMBIOSBIOSVersion, ReleaseDate