CVE-2021-4028 : Security Advisory and Response

A flaw in the Linux kernel's RDMA communications manager listener code allowed a local attacker to exploit a use-after-free vulnerability, potentially leading to system crashes or privilege escalation.

Understanding CVE-2021-4028

This section provides an overview of the impact, technical details, and mitigation strategies related to CVE-2021-4028.

What is CVE-2021-4028?

The vulnerability in the Linux kernel's RDMA communications manager listener code allowed a local attacker to abuse a use-after-free scenario, enabling the possibility of crashing the system or escalating privileges.

The Impact of CVE-2021-4028

The exploitation of this vulnerability could result in system instability, crashes, or unauthorized privilege escalation, posing a significant risk to affected systems.

Technical Details of CVE-2021-4028

Below are the technical specifics of CVE-2021-4028, including the vulnerability description, affected systems, and exploitation mechanism.

Vulnerability Description

The flaw in the implementation of the RDMA communications manager listener code in the Linux kernel allowed a local attacker to create a socket on a high port, leading to a use-after-free condition that could be leveraged for malicious activities.

Affected Systems and Versions

The vulnerability impacts the Linux kernel versions up to kernel 5.15-rc1. Systems running these versions are at risk of exploitation if accessed by a local attacker.

Exploitation Mechanism

By setting up a socket to listen on a high port, an attacker with local access could exploit the use-after-free vulnerability in the RDMA communications manager listener code to crash the system or potentially elevate their privileges.

Mitigation and Prevention

In response to CVE-2021-4028, it is crucial to take immediate steps, establish long-term security practices, and prioritize patching and updates to safeguard systems from known vulnerabilities.

Immediate Steps to Take

System administrators are advised to apply relevant patches and security updates provided by Linux vendors promptly to mitigate the risk of exploitation associated with CVE-2021-4028.

Long-Term Security Practices

Implementing security best practices, such as least privilege access, network segmentation, and regular security assessments, can enhance the overall resilience of systems against potential threats.

Patching and Updates

Regularly monitoring for security advisories and promptly applying patches and updates from reputable sources is essential to address known vulnerabilities and protect systems from potential cyber threats.