CVE-2021-38203 : Security Advisory and Response
Discover the impact of CVE-2021-38203 on Linux systems. Learn about the deadlock vulnerability in the btrfs filesystem of Linux kernel versions prior to 5.13.4 and how to mitigate the risks.
A denial of service vulnerability has been identified in the Linux kernel before version 5.13.4. Attackers can exploit this vulnerability in the btrfs filesystem to cause a deadlock by triggering the allocation of new system chunks when there is a shortage of free space.
Understanding CVE-2021-38203
This section delves deeper into the details related to CVE-2021-38203.
What is CVE-2021-38203?
The CVE-2021-38203 vulnerability exists in the btrfs filesystem of the Linux kernel prior to version 5.13.4. By inducing processes to request new system chunks at times of depleted free space in the system's space_info, attackers can lead to a denial of service situation.
The Impact of CVE-2021-38203
The impact of this CVE includes a denial of service (deadlock) scenario triggered by malicious actors exploiting system space chunk allocation during space shortages.
Technical Details of CVE-2021-38203
This section covers the technical aspects of the CVE in detail.
Vulnerability Description
The vulnerability in the btrfs filesystem allows attackers to instigate a deadlock by manipulating the allocation of new system chunks during periods of insufficient free space.
Affected Systems and Versions
The issue affects Linux kernel versions earlier than 5.13.4 that incorporate the btrfs filesystem.
Exploitation Mechanism
Attackers exploit the CVE-2021-38203 vulnerability by initiating processes that trigger the allocation of new system chunks when critical system space is lacking.
Mitigation and Prevention
Learn about the measures that can be taken to mitigate the risks associated with CVE-2021-38203.
Immediate Steps to Take
Immediate steps involve updating the Linux kernel to version 5.13.4 or newer to address the vulnerability and prevent potential deadlocks.
Long-Term Security Practices
Implementing regular security updates and monitoring system space allocation can help prevent exploitation of similar vulnerabilities in the future.
Patching and Updates
Stay informed about security advisories and promptly apply patches released by the Linux kernel maintainers to safeguard systems against known vulnerabilities.