CVE-2020-8336 Explained : Impact and Mitigation

Lenovo implemented Intel CSME Anti-rollback ARB protections on some ThinkPad models to prevent roll back of CSME Firmware in flash.

Understanding CVE-2020-8336

Lenovo BIOS firmware on certain ThinkPad models is affected by a vulnerability that could allow an attacker to roll back the CSME Firmware in flash.

What is CVE-2020-8336?

CVE-2020-8336 is a vulnerability in Lenovo BIOS firmware that could potentially lead to a rollback of the CSME Firmware in flash on specific ThinkPad models.

The Impact of CVE-2020-8336

The vulnerability has a CVSS base score of 6.4, indicating a medium severity issue with high impacts on confidentiality, integrity, and availability of affected systems.

Technical Details of CVE-2020-8336

Vulnerability Description

The vulnerability allows attackers to bypass Intel CSME Anti-rollback ARB protections on certain Lenovo ThinkPad models, enabling them to roll back CSME Firmware in flash.

Affected Systems and Versions

Product: BIOS
Vendor: Lenovo
Versions: Various

Exploitation Mechanism

The vulnerability requires physical access to the affected system to exploit the BIOS firmware.

Mitigation and Prevention

Immediate Steps to Take

Update system firmware to the version specified for your model in the Product Impact section of LEN-30042.

Long-Term Security Practices

Regularly update system firmware to the latest version provided by Lenovo.
Implement physical security measures to prevent unauthorized access to devices.

Patching and Updates

Lenovo has released patches to address the vulnerability. Ensure timely installation of firmware updates to mitigate the risk of exploitation.