CVE-2021-38201 Explained : Impact and Mitigation
Learn about CVE-2021-38201, a denial of service vulnerability in the Linux kernel before 5.13.4, allowing remote attackers to trigger a slab-out-of-bounds access in net/sunrpc/xdr.c.
A denial of service vulnerability, CVE-2021-38201, in the Linux kernel before version 5.13.4 has been identified. Attackers can exploit this vulnerability remotely, leading to a denial of service condition by triggering a slab-out-of-bounds access in net/sunrpc/xdr.c while performing NFS 4.2 READ_PLUS operations.
Understanding CVE-2021-38201
This section will provide insights into the nature and impact of CVE-2021-38201.
What is CVE-2021-38201?
The CVE-2021-38201 vulnerability is a denial of service flaw present in the Linux kernel prior to version 5.13.4. It allows remote attackers to exploit a slab-out-of-bounds access in net/sunrpc/xdr.c by executing numerous NFS 4.2 READ_PLUS operations.
The Impact of CVE-2021-38201
The impact of exploiting CVE-2021-38201 is severe, as it results in a denial of service condition within affected systems.
Technical Details of CVE-2021-38201
In this section, we delve into the technical aspects of CVE-2021-38201 to understand its implications further.
Vulnerability Description
The vulnerability arises from a flaw in net/sunrpc/xdr.c, allowing remote attackers to exploit it by executing multiple NFS 4.2 READ_PLUS operations, leading to a denial of service condition.
Affected Systems and Versions
All Linux kernel versions before 5.13.4 are affected by CVE-2021-38201, making them vulnerable to the denial of service exploit.
Exploitation Mechanism
Remote attackers can exploit this vulnerability by performing a large number of NFS 4.2 READ_PLUS operations, triggering the slab-out-of-bounds access in net/sunrpc/xdr.c.
Mitigation and Prevention
This section outlines the necessary steps to mitigate and prevent the exploitation of CVE-2021-38201.
Immediate Steps to Take
Users are advised to update their Linux kernel to version 5.13.4 or above to eliminate the vulnerability and prevent potential denial of service attacks.
Long-Term Security Practices
Maintaining an up-to-date kernel version, implementing network security measures, and monitoring NFS operations can enhance the long-term security posture of systems.
Patching and Updates
Regularly applying security patches released by Linux kernel maintainers is essential to address known vulnerabilities like CVE-2021-38201.