CVE-2020-8738 Overview
CVE-2020-8738 is a BIOS/UEFI vulnerability affecting Intel BIOS platform sample code for a wide range of Intel processors. The vulnerability stems from improper conditions check in the BIOS firmware, which may allow a privileged user to potentially enable escalation of privilege via local access. This vulnerability is classified under CWE-754 (Improper Check for Unusual or Exceptional Conditions).
Critical Impact
A privileged attacker with local access can exploit this firmware-level vulnerability to escalate privileges, potentially gaining higher-level system control and compromising the integrity of the underlying hardware platform.
Affected Products
- Intel BIOS Platform Sample Code
- Intel Core i5, i7, and i9 X-series Processors (various generations)
- Intel Xeon Scalable Processors (Bronze, Silver, Gold, Platinum series)
- Intel Xeon W, D, E5, and E7 Processor Families
- Intel Atom C3000 Series Processors
- NetApp FAS/AFF BIOS, HCI Compute Node BIOS, HCI Storage Node BIOS, SolidFire BIOS, and Cloud Backup
Discovery Timeline
- November 12, 2020 - CVE-2020-8738 published to NVD
- November 21, 2024 - Last updated in NVD database
Technical Details for CVE-2020-8738
Vulnerability Analysis
This vulnerability exists within the Intel BIOS platform sample code used across hundreds of Intel processor models spanning consumer, workstation, and enterprise server platforms. The flaw involves improper validation of conditions within the BIOS firmware, which fails to adequately check for unusual or exceptional states during execution.
The vulnerability requires local access and high privileges to exploit, meaning an attacker must already have some level of administrative access to the target system. However, successful exploitation can lead to complete compromise of confidentiality, integrity, and availability at the firmware level.
Firmware-level vulnerabilities are particularly concerning because they operate below the operating system, making them difficult to detect with traditional security tools and potentially allowing attackers to maintain persistence even through OS reinstallation.
Root Cause
The root cause of CVE-2020-8738 is classified as CWE-754: Improper Check for Unusual or Exceptional Conditions. The Intel BIOS platform sample code fails to properly validate certain conditions during execution, creating an opportunity for a privileged user to manipulate the system state in unintended ways.
This type of flaw typically occurs when firmware code assumes certain conditions will always be true or fails to implement proper bounds checking and state validation. When these assumptions are violated by a malicious actor, the firmware may enter an unexpected state that can be leveraged for privilege escalation.
Attack Vector
The attack requires local access to the target system with elevated privileges. An attacker with administrative access could potentially leverage this vulnerability to:
- Modify BIOS/UEFI settings in unauthorized ways
- Escalate privileges beyond their current access level
- Compromise firmware integrity
- Potentially establish persistent access below the operating system level
The local attack vector limits remote exploitation but makes this vulnerability relevant for insider threats, supply chain attacks, and scenarios where an attacker has already gained initial privileged access to a system.
Detection Methods for CVE-2020-8738
Indicators of Compromise
- Unexpected BIOS configuration changes or firmware modifications
- Anomalous system behavior during boot process or firmware updates
- Unauthorized access attempts to BIOS/UEFI management interfaces
- Firmware integrity check failures or hash mismatches
Detection Strategies
- Implement hardware-based attestation to verify firmware integrity at boot time
- Monitor for suspicious privileged account activity, particularly around BIOS/firmware management tools
- Deploy endpoint detection solutions capable of monitoring pre-boot and firmware-level activities
- Utilize Intel Platform Trust Technology (PTT) or TPM-based measured boot when available
Monitoring Recommendations
- Enable BIOS event logging and forward logs to a centralized SIEM solution
- Establish baseline firmware configurations and alert on deviations
- Monitor administrative access to systems containing affected processors, particularly in data center environments
- Implement change management processes for any firmware updates
How to Mitigate CVE-2020-8738
Immediate Actions Required
- Inventory all systems containing affected Intel processors and identify current BIOS versions
- Apply updated BIOS firmware from your system manufacturer that addresses this vulnerability
- Restrict administrative access to affected systems to essential personnel only
- Enable BIOS password protection and Secure Boot features where supported
Patch Information
Intel has released updated BIOS platform sample code to address this vulnerability. System administrators should obtain updated BIOS firmware from their OEM or motherboard manufacturer rather than directly from Intel, as the fix must be incorporated into vendor-specific BIOS implementations.
For detailed patch information, refer to the Intel Security Advisory INTEL-SA-00390. NetApp customers should also review the NetApp Security Advisory NTAP-20210122-0008 for affected storage and compute products.
Workarounds
- Implement strict physical access controls to prevent unauthorized local access to affected systems
- Enable BIOS/UEFI password protection to prevent unauthorized configuration changes
- Deploy endpoint protection solutions with firmware integrity monitoring capabilities
- Consider network segmentation to isolate systems with affected processors from untrusted network segments
# Example: Check current BIOS version on Linux systems
dmidecode -t bios | grep -E "Vendor|Version|Release"
# Example: Verify Secure Boot status
mokutil --sb-state
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
