CVE-2021-20203 : Security Advisory and Response
Learn about CVE-2021-20203, an integer overflow issue in the QEMU vmxnet3 NIC emulator up to v5.2.0, allowing DoS attacks. Find mitigation steps and security practices.
An integer overflow issue was found in the vmxnet3 NIC emulator of the QEMU for versions up to v5.2.0. A privileged guest user could exploit this flaw to crash the QEMU process on the host, resulting in a Denial of Service (DoS) scenario.
Understanding CVE-2021-20203
This section provides insights into the nature and impact of the CVE-2021-20203 vulnerability.
What is CVE-2021-20203?
CVE-2021-20203 is an integer overflow issue identified in the vmxnet3 NIC emulator of QEMU versions up to v5.2.0. It could be triggered by a privileged guest user providing invalid values for rx/tx queue size or other NIC parameters.
The Impact of CVE-2021-20203
The impact of this vulnerability is the potential for a DoS scenario, where the QEMU process on the host could crash due to exploitation by a malicious privileged guest user.
Technical Details of CVE-2021-20203
In this section, we delve into the specifics of the CVE-2021-20203 vulnerability.
Vulnerability Description
The vulnerability arises from an integer overflow issue in the vmxnet3 NIC emulator of QEMU versions up to v5.2.0, allowing a privileged guest user to trigger a crash in the QEMU process.
Affected Systems and Versions
QEMU versions up to v5.2.0 are affected by CVE-2021-20203 due to the identified integer overflow issue in the vmxnet3 NIC emulator.
Exploitation Mechanism
Malicious exploitation of this vulnerability involves a privileged guest user providing invalid values for rx/tx queue size or other NIC parameters, leading to a potential DoS scenario.
Mitigation and Prevention
This section outlines the steps that can be taken to mitigate the risks associated with CVE-2021-20203.
Immediate Steps to Take
Users are advised to update QEMU to a version beyond v5.2.0 to address and remediate the integer overflow issue in the vmxnet3 NIC emulator.
Long-Term Security Practices
Implementing best security practices, such as regular software updates, network segmentation, and user privilege management, can enhance overall system security and resilience.
Patching and Updates
Regularly monitor and apply security patches and updates released by QEMU to stay protected against known vulnerabilities like CVE-2021-20203.