CVE-2022-23924: HP PC BIOS Privilege Escalation Flaw

CVE-2022-23924 Overview

CVE-2022-23924 is a BIOS/UEFI vulnerability affecting certain HP PC products. This vulnerability in the system BIOS may allow attackers to achieve escalation of privilege, arbitrary code execution, unauthorized code execution, denial of service, and information disclosure. The local attack vector requires high privileges but can impact system confidentiality, integrity, and availability beyond the vulnerable component's scope.

Critical Impact

Successful exploitation could allow attackers with local access and high privileges to execute arbitrary code at the BIOS level, potentially compromising the entire system's security foundation and persisting across operating system reinstalls.

Affected Products

• HP PC BIOS (multiple product lines)
• Various HP PC systems with affected BIOS versions
• HP commercial and consumer PC products

Discovery Timeline

• 2022-03-11 - CVE-2022-23924 published to NVD
• 2024-11-21 - Last updated in NVD database

Technical Details for CVE-2022-23924

Vulnerability Analysis

This BIOS/UEFI vulnerability affects the system firmware of certain HP PC products. BIOS-level vulnerabilities are particularly dangerous because they operate at the lowest level of the software stack, below the operating system. An attacker who successfully exploits this vulnerability could gain persistent access that survives operating system reinstallation and even disk replacement in some cases.

The vulnerability requires local access and high privileges to exploit, which limits the attack surface. However, the scope change indicated in the security assessment means that successful exploitation can affect resources beyond the vulnerable BIOS component itself, potentially compromising the entire system including the operating system and all installed applications.

Root Cause

The specific technical root cause has not been publicly disclosed by HP. BIOS vulnerabilities typically arise from issues such as improper input validation in System Management Mode (SMM) handlers, insecure memory protections, improper access controls on BIOS update mechanisms, or flaws in secure boot implementation. Without detailed technical information from the vendor, the exact mechanism remains undisclosed.

Attack Vector

The vulnerability requires local access to the affected system with high privileges. Potential attack scenarios include:

• A malicious administrator or insider with elevated access exploiting the vulnerability
• An attacker who has already gained high-privilege access through another vulnerability chain
• Physical access scenarios where an attacker can interact with the system BIOS
• Malware that has achieved system-level privileges attempting to establish BIOS-level persistence

The local attack requirement and high privilege prerequisite significantly reduce the risk of opportunistic exploitation, but targeted attacks against high-value systems remain a concern.

Detection Methods for CVE-2022-23924

Indicators of Compromise

• Unexpected BIOS firmware version changes or modifications
• Anomalous system behavior during boot sequences
• Unauthorized changes to BIOS settings or secure boot configuration
• Unexpected SMM (System Management Mode) activity

Detection Strategies

• Implement firmware integrity monitoring to detect unauthorized BIOS modifications
• Enable and monitor Trusted Platform Module (TPM) measurements for boot integrity
• Deploy endpoint detection solutions capable of monitoring firmware-level changes
• Review system logs for unusual BIOS-related events or error messages

Monitoring Recommendations

• Establish baseline BIOS versions across all HP PC systems in your environment
• Configure alerts for any BIOS firmware update events outside of authorized maintenance windows
• Monitor for processes attempting to access or modify BIOS-related system interfaces
• Implement hardware security monitoring where available (TPM attestation, secure boot logs)

How to Mitigate CVE-2022-23924

Immediate Actions Required

• Identify all HP PC systems in your environment that may be affected
• Review the HP Security Advisory to determine if your specific models are vulnerable
• Prioritize patching for systems in high-security environments or those accessible to untrusted users
• Restrict local administrative access to affected systems until patches are applied

Patch Information

HP has released BIOS updates to address this vulnerability. System administrators should download the appropriate BIOS update for their specific HP PC models from the official HP support website. The detailed list of affected products and corresponding firmware updates is available in the HP Security Document.

When applying BIOS updates:

1. Ensure systems are connected to a reliable power source
2. Back up current BIOS settings before updating
3. Follow HP's official BIOS update procedures for your specific model
4. Verify the update was successful by checking the BIOS version post-update

Workarounds

• Restrict physical access to affected systems
• Implement strong access controls to limit users with administrative privileges
• Enable BIOS password protection to prevent unauthorized configuration changes
• Deploy endpoint protection solutions to detect and prevent privilege escalation attempts that could lead to BIOS-level exploitation

BIOS security configuration should include:

• Setting a strong BIOS administrator password
• Enabling Secure Boot if supported
• Disabling unnecessary BIOS features that could increase attack surface
• Configuring boot order to prevent unauthorized boot media