CVE-2025-27243 is a firmware vulnerability in Intel Ethernet Controller E810 devices, specifically in versions prior to cvl fw 1.7.8.x. The flaw is an out-of-bounds write occurring within the firmware operating at Ring 0 on Bare Metal OS environments. This vulnerability can be exploited by a system software adversary who has privileged user access (high privileges) on the local machine. The attack complexity is low, requiring no user interaction or special internal knowledge, making it feasible for insiders or compromised privileged accounts. The primary impact is denial of service, as the out-of-bounds write can cause system instability or crashes, affecting the availability of the network interface and potentially the host system relying on it. Confidentiality and integrity are not impacted by this vulnerability. The CVSS 4.0 base score is 6.7, reflecting a medium severity level due to the requirement of privileged access and local attack vector. No public exploits have been reported yet, but the vulnerability warrants attention due to the critical role of network controllers in enterprise and data center environments. Firmware updates addressing this issue have been released in version 1.7.8.x and later, and applying these patches is essential to mitigate the risk.

For European organizations, the primary impact of CVE-2025-27243 is the potential disruption of network availability due to denial of service conditions on systems using vulnerable Intel Ethernet Controller E810 firmware. This can affect data centers, enterprise servers, and critical infrastructure relying on these network controllers for stable connectivity. Service interruptions may lead to operational downtime, impacting business continuity, especially in sectors like finance, telecommunications, healthcare, and government services. Since the vulnerability requires privileged local access, the risk is heightened in environments where insider threats or compromised administrative accounts exist. Although confidentiality and integrity are not directly affected, the loss of availability can indirectly impact organizational operations and service delivery. The absence of known exploits reduces immediate risk but does not eliminate the need for proactive mitigation. Organizations with extensive deployments of Intel Ethernet Controller E810 hardware should prioritize firmware updates to prevent potential exploitation.

1. Immediately verify the firmware version of Intel Ethernet Controller E810 devices and upgrade to version cvl fw 1.7.8.x or later where the vulnerability is patched. 2. Restrict and monitor privileged user access on systems with affected hardware to reduce the risk of local exploitation. 3. Implement strict access controls and auditing for administrative accounts to detect and prevent unauthorized privilege escalation. 4. Employ network segmentation to isolate critical systems using vulnerable controllers, limiting the impact of potential denial of service events. 5. Regularly review and update firmware and driver inventories as part of asset management to ensure timely patching of vulnerabilities. 6. Conduct internal security awareness training emphasizing the risks of privileged account misuse. 7. Monitor system logs and network behavior for signs of instability or unusual activity that could indicate exploitation attempts. 8. Coordinate with Intel and hardware vendors for any additional security advisories or mitigations related to this vulnerability.