CVE-2021-3491 Explained : Impact and Mitigation
Explore the impact of CVE-2021-3491 on the Linux kernel's io_uring subsystem, its severity, affected versions, and mitigation strategies. Learn how to secure your systems effectively.
A detailed overview of CVE-2021-3491 impacting the Linux kernel's io_uring subsystem.
Understanding CVE-2021-3491
This section provides insights into the nature and impact of the vulnerability.
What is CVE-2021-3491?
The io_uring subsystem in the Linux kernel allowed the MAX_RW_COUNT limit to be bypassed in the PROVIDE_BUFFERS operation. This could lead to negative values being used in mem_rw, resulting in a heap overflow and potential arbitrary code execution in the kernel.
The Impact of CVE-2021-3491
The vulnerability scored a CVSS base score of 7.8, indicating a high severity issue. It has a high impact on confidentiality, integrity, and availability, with a low level of privileges required for exploitation.
Technical Details of CVE-2021-3491
Exploring the specifics of the CVE-2021-3491 vulnerability.
Vulnerability Description
CVE-2021-3491 bypassed the MAX_RW_COUNT limit in the PROVIDE_BUFFERS operation, leading to a heap overflow and the potential execution of arbitrary code within the Linux kernel.
Affected Systems and Versions
The vulnerability affects Linux kernel versions v5.13-rc4 (trunk), v5.12.4 (linux-5.12.y), v5.11.21 (linux-5.11.y), v5.10.37 (linux-5.10.y), and v5.7-rc1.
Exploitation Mechanism
Attackers could exploit this vulnerability locally, requiring a low level of privileges. The issue involves changing the scope within the Linux kernel, allowing for effective attacks.
Mitigation and Prevention
Understanding the steps to mitigate and prevent exploitation of CVE-2021-3491.
Immediate Steps to Take
Users are advised to apply the necessary patches provided by Linux for the affected kernel versions. Ensure prompt updates to prevent exploitation by threat actors.
Long-Term Security Practices
Institute robust security practices, including regular monitoring, access control measures, and threat intelligence integration to enhance overall system security.
Patching and Updates
Regularly monitor and apply updates and patches released by Linux to address vulnerabilities like CVE-2021-3491 and ensure the security of your systems.