CVE-2021-26315 : What You Need to Know

This article provides details about CVE-2021-26315, a security vulnerability affecting 3rd Gen AMD EPYC processors. It discusses the impact, technical details, and mitigation methods related to this CVE.

Understanding CVE-2021-26315

CVE-2021-26315 is a vulnerability in AMD Platform Security Processor affecting certain versions of 3rd Gen AMD EPYC processors.

What is CVE-2021-26315?

The vulnerability arises when the AMD Platform Security Processor boot rom fails to sufficiently verify the integrity of decrypted firmware images. This can lead to the execution of arbitrary code within the PSP when encrypted firmware images are utilized.

The Impact of CVE-2021-26315

The lack of proper verification in the PSP boot rom allows threat actors to potentially execute malicious code, compromising the security and integrity of systems using affected AMD processors.

Technical Details of CVE-2021-26315

The following technical aspects are associated with CVE-2021-26315:

Vulnerability Description

Insufficient verification of the decrypted image's integrity during the boot process of AMD PSP, enabling the execution of arbitrary code using encrypted firmware images.

Affected Systems and Versions

3rd Gen AMD EPYC processors before the MilanPI-SP3_1.0.0.4 version are impacted by this vulnerability.

Exploitation Mechanism

Threat actors can exploit this vulnerability by leveraging the lack of adequate integrity verification in the AMD PSP boot rom to execute arbitrary code.

Mitigation and Prevention

To address CVE-2021-26315, consider the following mitigation strategies:

Immediate Steps to Take

AMD recommends updating the affected systems with the latest patches and firmware versions from AMD.
Monitor for any unusual PSP behavior that could indicate exploitation of the vulnerability.

Long-Term Security Practices

Regularly apply security updates provided by AMD to ensure protection against known vulnerabilities.
Implement secure boot mechanisms to enhance the overall system security.

Patching and Updates

Stay informed about security advisories from AMD and promptly apply recommended patches and updates to safeguard systems.