CVE-2025-27243: Intel E810 Ethernet Controller DoS Flaw

CVE-2025-27243 Overview

CVE-2025-27243 is an out-of-bounds write vulnerability affecting the firmware for Intel(R) Ethernet Controller E810 series devices. This firmware vulnerability exists within Ring 0 (Bare Metal OS) and can be exploited by privileged local attackers to cause a denial of service condition. The vulnerability stems from improper boundary checking during write operations in the firmware, allowing memory corruption that can impact system availability.

Critical Impact

A privileged local attacker can exploit this out-of-bounds write vulnerability to cause denial of service on systems utilizing Intel E810 Ethernet Controllers, potentially disrupting critical network connectivity.

Affected Products

• Intel(R) Ethernet Controller E810 with firmware versions before cvl fw 1.7.8.x
• Systems running Intel E810 series network adapters in bare metal configurations
• Enterprise and data center environments utilizing Intel E810 NICs

Discovery Timeline

• 2026-02-10 - CVE-2025-27243 published to NVD
• 2026-02-10 - Last updated in NVD database

Technical Details for CVE-2025-27243

Vulnerability Analysis

This vulnerability is classified as CWE-787 (Out-of-bounds Write), a memory corruption issue that occurs when the firmware writes data past the boundaries of allocated memory buffers. In the context of the Intel E810 Ethernet Controller firmware, this flaw exists within Ring 0 execution context, which represents the most privileged level of operation on the processor.

The vulnerability requires local access and high privileges to exploit, meaning an attacker must already have administrative or root-level access to the target system. While the attack complexity is low and no user interaction is required, the impact is limited to availability—confidentiality and integrity remain unaffected. Successfully exploiting this vulnerability results in a denial of service condition, potentially disrupting network connectivity for affected systems.

Root Cause

The root cause of CVE-2025-27243 lies in insufficient bounds checking within the Intel E810 Ethernet Controller firmware. During certain write operations, the firmware fails to properly validate the size or destination of data being written to memory buffers. This allows data to be written beyond the intended memory boundaries, corrupting adjacent memory regions and potentially causing the firmware or system to crash.

Attack Vector

The attack vector for this vulnerability is local, requiring the attacker to have privileged access to the target system. The exploitation scenario involves a system software adversary with elevated privileges who can interact with the Ethernet controller firmware through system interfaces. The attack does not require special internal knowledge or user interaction, making it relatively straightforward for an attacker who has already gained privileged access to the system.

The vulnerability affects systems where the Intel E810 Ethernet Controller operates in bare metal configurations, which is common in high-performance computing, data center, and enterprise network environments where maximum network throughput is required.

Detection Methods for CVE-2025-27243

Indicators of Compromise

• Unexpected system crashes or blue screens on systems with Intel E810 Ethernet Controllers
• Network interface failures or disconnections without hardware issues
• Firmware error messages in system logs related to Intel E810 adapters
• Unusual memory access patterns detected by endpoint detection and response (EDR) solutions

Detection Strategies

• Monitor system event logs for firmware crashes or errors related to Intel E810 network adapters
• Implement firmware version auditing to identify systems running vulnerable firmware versions prior to cvl fw 1.7.8.x
• Deploy SentinelOne Singularity Platform to detect anomalous behavior patterns associated with local privilege abuse
• Utilize hardware inventory tools to track Intel E810 controller deployments across the enterprise

Monitoring Recommendations

• Enable verbose logging for network adapter firmware events and system crashes
• Configure alerting for repeated network interface failures on systems with Intel E810 controllers
• Implement regular firmware version scanning as part of vulnerability management programs
• Monitor for unusual privileged operations targeting network device interfaces

How to Mitigate CVE-2025-27243

Immediate Actions Required

• Update Intel E810 Ethernet Controller firmware to version cvl fw 1.7.8.x or later immediately
• Conduct an inventory of all systems utilizing Intel E810 series network adapters
• Prioritize patching for systems in critical infrastructure or high-availability environments
• Restrict local administrative access to reduce the attack surface for privileged attackers

Patch Information

Intel has released a firmware update to address this vulnerability. Organizations should update to firmware version cvl fw 1.7.8.x or later. The security advisory and firmware updates are available through the Intel Security Advisory INTEL-SA-01171. System administrators should follow Intel's firmware update procedures and ensure proper backup and rollback capabilities are in place before applying updates.

Workarounds

• Restrict local administrative privileges to minimize the number of users who could potentially exploit this vulnerability
• Implement network segmentation to limit the impact of potential denial of service conditions
• Deploy redundant network connectivity using non-affected network adapters where possible
• Monitor affected systems closely until firmware updates can be applied

Firmware updates should be applied following Intel's official documentation and validated in a test environment before deployment to production systems. Always ensure proper change management procedures are followed when updating firmware on critical infrastructure components.