CVE-2021-38202 : Vulnerability Insights and Analysis

A denial of service vulnerability has been discovered in the Linux kernel prior to version 5.13.4, known as CVE-2021-38202. Attackers can exploit this flaw by sending NFS traffic when the trace event framework is being used for nfsd.

Understanding CVE-2021-38202

This section will delve into the details of the CVE-2021-38202 vulnerability.

What is CVE-2021-38202?

CVE-2021-38202 is a denial of service vulnerability found in fs/nfsd/trace.h in the Linux kernel before version 5.13.4. It could potentially allow remote attackers to trigger an out-of-bounds read in strlen by sending NFS traffic while the trace event framework is active for nfsd.

The Impact of CVE-2021-38202

Exploitation of this vulnerability could lead to a denial of service condition, disrupting the normal operation of affected systems.

Technical Details of CVE-2021-38202

Here we will explore the technical specifics of CVE-2021-38202.

Vulnerability Description

The vulnerability in fs/nfsd/trace.h in the Linux kernel version prior to 5.13.4 could be exploited by malicious actors through sending NFS traffic during the utilization of the trace event framework for nfsd, resulting in an out-of-bounds read in strlen.

Affected Systems and Versions

All systems running on Linux kernel versions prior to 5.13.4 are vulnerable to this denial of service flaw if NFS traffic is being processed while using the trace event framework for nfsd.

Exploitation Mechanism

Attackers can exploit CVE-2021-38202 by sending malicious NFS traffic when the trace event framework is active for nfsd, leading to an out-of-bounds read vulnerability in strlen.

Mitigation and Prevention

In this section, we will cover the necessary steps to mitigate and prevent exploitation of CVE-2021-38202.

Immediate Steps to Take

System administrators are advised to update their Linux kernel to version 5.13.4 or later to prevent exploitation of this vulnerability. Additionally, monitoring NFS traffic and disabling the trace event framework for nfsd can help mitigate the risk.

Long-Term Security Practices

Regularly updating the Linux kernel and implementing strong network security measures are essential for maintaining overall system security and resilience against potential threats.

Patching and Updates

Keep systems up to date with the latest security patches to ensure that known vulnerabilities like CVE-2021-38202 are addressed promptly and effectively.