CVE-2021-20292 : Vulnerability Insights and Analysis

This CVE-2021-20292 article provides an overview of a flaw in the Linux kernel, affecting versions before 5.9, with the potential for privilege escalation and code execution.

Understanding CVE-2021-20292

This section delves into the details of the vulnerability reported in the Linux kernel and its implications.

What is CVE-2021-20292?

CVE-2021-20292 is a vulnerability found in the Linux kernel versions preceding 5.9, specifically in drivers/gpu/drm/nouveau/nouveau_sgdma.c in nouveau_sgdma_create_ttm in the Nouveau DRM subsystem. The issue arises due to insufficient validation of object existence before executing operations, enabling a local attacker with root privileges to elevate their rights and run code within the kernel's context.

The Impact of CVE-2021-20292

The impact of this vulnerability is critical as it allows a malicious actor to exploit the flaw and potentially carry out privilege escalation attacks, leading to unauthorized access and execution of arbitrary code on the affected system.

Technical Details of CVE-2021-20292

In this section, we discuss the technical aspects of CVE-2021-20292, covering the vulnerability description, affected systems, versions, and the exploitation mechanism.

Vulnerability Description

The vulnerability in Nouveau DRM subsystem arises from the failure to validate the existence of an object before performing operations, facilitating an attacker with local root privileges to escalate their rights and execute malicious code within the kernel.

Affected Systems and Versions

The flaw impacts Linux kernel versions before 5.9, particularly in drivers/gpu/drm/nouveau/nouveau_sgdma.c in nouveau_sgdma_create_ttm within the Nouveau DRM subsystem, making systems running these versions vulnerable to exploitation.

Exploitation Mechanism

Attackers with local accounts and root privileges can leverage this vulnerability to bypass security measures, elevate their privileges, and execute arbitrary code within the kernel, potentially leading to system compromise.

Mitigation and Prevention

This section outlines steps to mitigate the risk posed by CVE-2021-20292, including immediate actions and long-term security practices.

Immediate Steps to Take

To address CVE-2021-20292, users are advised to apply security patches or updates provided by the respective vendors promptly. Additionally, restricting access and permissions to critical system components can help reduce the likelihood of successful exploitation.

Long-Term Security Practices

Implementing strong access controls, regular security audits, and staying informed about the latest security threats can enhance the overall security posture of systems, reducing the risk of vulnerabilities such as CVE-2021-20292.

Patching and Updates

Regularly updating the Linux kernel to versions that include fixes for CVE-2021-20292 is crucial in preventing exploitation. Vendors often release patches and updates to address such vulnerabilities, and users must ensure timely installation of these security fixes.