CVE-2021-4218 : Security Advisory and Response
Discover how CVE-2021-4218 impacts CentOS/RHEL systems with a flaw in the Linux kernel leading to a denial of service attack. Learn about mitigation strategies.
A flaw in the Linux kernel's implementation of reading SVC RDMA counters can lead to a denial of service attack. This vulnerability affects CentOS/RHEL systems and allows a local attacker to trigger a system panic resulting in a reboot.
Understanding CVE-2021-4218
This CVE describes a specific flaw in the Linux kernel that can be exploited locally to cause a denial of service attack on affected systems.
What is CVE-2021-4218?
CVE-2021-4218 is a vulnerability in the Linux kernel that arises from improper handling of SVC RDMA counters, leading to a system panic and subsequent denial of service during reboot.
The Impact of CVE-2021-4218
The impact of this vulnerability is significant as it allows a local attacker to exploit the flaw and disrupt system availability by forcing a reboot.
Technical Details of CVE-2021-4218
This section provides detailed technical information about the CVE.
Vulnerability Description
The vulnerability originates from a flaw in the code responsible for reading the SVC RDMA counters in the Linux kernel, which results in a system panic when accessed.
Affected Systems and Versions
CentOS/RHEL systems are specifically affected by this vulnerability, with a potential impact on the stability and availability of these systems.
Exploitation Mechanism
Local attackers with access to the system can exploit this vulnerability by triggering the reading of SVC RDMA counters, causing the system to panic and undergo a denial of service while rebooting.
Mitigation and Prevention
Understanding how to mitigate and prevent CVE-2021-4218 is crucial for maintaining system security.
Immediate Steps to Take
As a mitigation measure, it is recommended to apply relevant patches and updates provided by the vendor to address this vulnerability.
Long-Term Security Practices
Adopting robust security practices, such as regular system updates and security monitoring, can help in preventing and detecting potential vulnerabilities in the future.
Patching and Updates
Regularly checking for and applying available security patches and updates for the Linux kernel can help in securing the system against known vulnerabilities.