CVE-2021-36323 : Security Advisory and Response

Dell BIOS contains a vulnerability due to improper input validation that allows a local authenticated malicious user to potentially execute arbitrary code in SMRAM using an SMI.

Understanding CVE-2021-36323

This section will provide an overview of CVE-2021-36323, including its impact and technical details.

What is CVE-2021-36323?

The CVE-2021-36323 vulnerability is found in Dell BIOS, where an improper input validation flaw exists. Attackers with local access and proper authentication can leverage this vulnerability to execute arbitrary code using System Management Interrupts (SMI) and compromise the Secure Memory Random Access Memory (SMRAM).

The Impact of CVE-2021-36323

The impact of this vulnerability is rated as high, with a CVSS base score of 7.5. The attack complexity is high, requiring high privileges and resulting in high confidentiality, integrity, and availability impact. The scope of the attack is changed without requiring any user interaction.

Technical Details of CVE-2021-36323

In this section, we will delve into the technical aspects of CVE-2021-36323, including the vulnerability description, affected systems, and exploitation mechanism.

Vulnerability Description

The vulnerability arises from improper input validation in Dell BIOS, enabling an authenticated local user to trigger arbitrary code execution through SMI in SMRAM.

Affected Systems and Versions

The affected product is CPG BIOS by Dell, specifically versions less than 1.13.0. Users with custom versions are also susceptible to this vulnerability.

Exploitation Mechanism

To exploit CVE-2021-36323, a malicious user must already have local access and authentication to the system. By using an SMI, they can execute arbitrary code within the SMRAM, leading to a security breach.

Mitigation and Prevention

This section outlines the necessary steps to mitigate and prevent the exploitation of CVE-2021-36323, safeguarding systems from potential attacks.

Immediate Steps to Take

Users are advised to update their Dell BIOS to version 1.13.0 or higher to mitigate the vulnerability. Additionally, restrict physical access to authorized personnel only.

Long-Term Security Practices

Implement strict access control policies, conduct regular security audits, and educate users on best security practices to enhance overall system security.

Patching and Updates

Stay informed about security updates from Dell and promptly apply patches to ensure protection against known vulnerabilities.