CVE-2020-8670 Overview
CVE-2020-8670 is a race condition vulnerability in the firmware for certain Intel Processors. A privileged local user can exploit timing windows in firmware execution to achieve escalation of privilege. The flaw is categorized under CWE-362 (Concurrent Execution using Shared Resource with Improper Synchronization).
The vulnerability affects a wide range of Intel CPUs, including Core i7, Core i9, Xeon Bronze, Silver, Gold, Platinum, Xeon D, Xeon E, Xeon W, and Xeon E3/E5/E7 product lines. Downstream impacts extend to Siemens SIMATIC industrial PCs and NetApp BIOS-based products that rely on the affected Intel firmware.
Critical Impact
A privileged local actor can leverage a firmware race condition to escalate privileges, potentially gaining control below the operating system boundary.
Affected Products
- Intel BIOS and multiple Intel processor families (Core i3/i5/i7/i9, Xeon Bronze/Silver/Gold/Platinum, Xeon D/E/W, Xeon E3/E5/E7)
- Siemens SIMATIC industrial PCs (IPC427E, IPC477E, IPC527G, IPC547G, IPC627E, IPC647E, IPC677E, IPC847E, ITP1000, Field PG M6)
- NetApp AFF BIOS, FAS BIOS, HCI Compute/Storage Node BIOS, SolidFire BIOS, and Cloud Backup
Discovery Timeline
- 2021-06-09 - CVE-2020-8670 published to NVD
- 2024-11-21 - Last updated in NVD database
Technical Details for CVE-2020-8670
Vulnerability Analysis
The vulnerability resides in Intel processor firmware execution paths. Two or more concurrent operations interact with shared firmware resources without proper synchronization. An attacker holding high privileges on the local system can manipulate the timing of these operations to enter an unintended state.
Exploitation requires local access and existing high privileges, narrowing the threat to insiders, compromised administrators, or malware that has already achieved a privileged foothold. The attack complexity is high because the attacker must reliably win a narrow timing window in firmware code.
Successful exploitation impacts confidentiality, integrity, and availability of the system. Because the flaw lives in firmware, compromise can persist below the operating system, including BIOS-level execution contexts that traditional host security controls cannot fully observe.
Root Cause
The root cause is improper synchronization of shared firmware state during concurrent execution. The firmware fails to enforce atomicity between a check and a subsequent operation, creating a Time-of-Check to Time-of-Use (TOCTOU) condition that a privileged caller can exercise.
Attack Vector
The attack vector is local. An attacker must already possess high privileges on the target system and execute code that repeatedly invokes the vulnerable firmware path. By racing the firmware operation, the attacker manipulates shared state and elevates privileges further, potentially crossing the OS-firmware boundary.
No public proof-of-concept exploit is listed for CVE-2020-8670, and the vulnerability is not present on the CISA Known Exploited Vulnerabilities list. See the Intel Security Advisory SA-00463 for vendor-confirmed technical details.
Detection Methods for CVE-2020-8670
Indicators of Compromise
- Unexpected firmware version mismatches between deployed systems and the vendor-approved baseline
- Unauthorized BIOS/UEFI configuration changes or signs of firmware reflash activity outside maintenance windows
- Repeated invocation of low-level system management calls by privileged user processes
Detection Strategies
- Inventory firmware and microcode versions across the fleet and compare against the patched versions documented in Intel SA-00463
- Monitor for privileged process behavior that issues repeated, tight loops against firmware interfaces, which is characteristic of race condition exploitation
- Use platform attestation (TPM measurements, Intel Boot Guard logs) to validate firmware integrity at boot
Monitoring Recommendations
- Centralize firmware and BIOS version telemetry alongside endpoint logs to identify unpatched systems
- Alert on administrative account activity that touches BIOS update utilities or firmware-related kernel interfaces outside of approved change windows
- Track audit trails for local privilege escalation events that correlate with firmware-level operations
How to Mitigate CVE-2020-8670
Immediate Actions Required
- Apply the firmware/BIOS updates published by Intel and downstream OEMs to all affected Intel processor SKUs
- Apply Siemens firmware updates referenced in Siemens Security Advisory SSA-309571 for affected SIMATIC industrial PCs
- Apply NetApp BIOS updates referenced in NetApp Security Advisory NTAP-20210702-0002
- Restrict and audit local administrative access on systems running affected Intel processors
Patch Information
Intel released firmware updates as documented in Intel Security Advisory SA-00463. System integrators including Siemens and NetApp shipped corresponding BIOS updates for their affected platforms. Deploy the vendor-supplied BIOS package matching the exact platform and processor SKU.
Workarounds
- Enforce least privilege for local accounts to reduce the population of users who meet the high-privilege precondition
- Enable platform integrity features such as Intel Boot Guard, Secure Boot, and TPM-based measured boot to detect unauthorized firmware modification
- Isolate critical industrial and storage systems on segmented networks until firmware patches are applied
# Verify BIOS/firmware version on Linux to compare against vendor patch baseline
sudo dmidecode -s bios-version
sudo dmidecode -s bios-release-date
sudo dmidecode -s processor-version
# Windows equivalent (PowerShell)
# Get-WmiObject Win32_BIOS | Select-Object Manufacturer, SMBIOSBIOSVersion, ReleaseDate
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
