CVE-2021-20221 Explained : Impact and Mitigation
Learn about CVE-2021-20221, an out-of-bounds heap buffer access vulnerability in the ARM Generic Interrupt Controller emulator of QEMU. Understand the impact, affected systems, and mitigation steps.
An out-of-bounds heap buffer access vulnerability was discovered in the ARM Generic Interrupt Controller emulator of QEMU up to and including version 4.2.0 on the aarch64 platform. This vulnerability could be exploited by a privileged guest user to crash the QEMU process on the host, leading to a Denial of Service (DoS) scenario.
Understanding CVE-2021-20221
This section provides insights into the nature and impact of the CVE-2021-20221 vulnerability.
What is CVE-2021-20221?
CVE-2021-20221 is an out-of-bounds heap buffer access vulnerability present in the ARM Generic Interrupt Controller emulator of QEMU versions up to and including qemu 4.2.0 on the aarch64 platform. It arises due to a flaw in handling interrupt ID field masking, potentially leading to a crash of the QEMU process.
The Impact of CVE-2021-20221
Exploitation of this vulnerability by a privileged guest user could result in a DoS scenario by crashing the QEMU process on the host system.
Technical Details of CVE-2021-20221
This section delves into the technical aspects of the CVE-2021-20221 vulnerability.
Vulnerability Description
The vulnerability occurs due to an out-of-bounds heap buffer access issue in the ARM Generic Interrupt Controller emulator of QEMU versions up to and including qemu 4.2.0 on the aarch64 platform. The flaw arises from the improper handling of interrupt ID masking, potentially leading to a crash of the host QEMU process.
Affected Systems and Versions
QEMU versions up to and including 4.2.0 on the aarch64 platform are impacted by this vulnerability.
Exploitation Mechanism
A privileged guest user could exploit this vulnerability by manipulating the interrupt ID field in a way that triggers the out-of-bounds heap buffer access, ultimately leading to a crash of the QEMU process.
Mitigation and Prevention
This section outlines the steps to mitigate and prevent the exploitation of CVE-2021-20221.
Immediate Steps to Take
Users and administrators are advised to apply the necessary security updates provided by QEMU to address this vulnerability effectively.
Long-Term Security Practices
Maintaining up-to-date software versions and implementing secure coding practices can help prevent similar vulnerabilities in the future.
Patching and Updates
Ensure that QEMU is updated to versions beyond 4.2.0 to patch the vulnerability and enhance the security posture of the system.