CVE-2021-3527 : Vulnerability Insights and Analysis

A flaw was found in the USB redirector device (usb-redir) of QEMU. This CVE affects all versions of QEMU. The vulnerability allows a malicious guest to influence the array length and cause excessive allocation on the stack, resulting in a denial of service.

Understanding CVE-2021-3527

This section will cover the details of the CVE-2021-3527 vulnerability, its impact, technical description, affected systems, exploitation mechanism, mitigation, and prevention methods.

What is CVE-2021-3527?

The vulnerability in the USB redirector device of QEMU allows a malicious guest to perform an excessive allocation on the stack by influencing the array length dynamically.

The Impact of CVE-2021-3527

Exploitation of this vulnerability can lead to a denial of service, impacting the availability of the QEMU process.

Technical Details of CVE-2021-3527

The technical details of CVE-2021-3527 include vulnerability description, affected systems and versions, and exploitation mechanism.

Vulnerability Description

QEMU combines small USB packets into a single large transfer request without proper validation, leading to excessive allocation on the stack.

Affected Systems and Versions

All versions of QEMU are affected by CVE-2021-3527 due to the flaw in the USB redirector device.

Exploitation Mechanism

A malicious guest can influence the array length dynamically, causing the QEMU process to perform an excessive allocation on the stack, resulting in a denial of service.

Mitigation and Prevention

This section will outline immediate steps to take, long-term security practices, and the importance of patching and updates.

Immediate Steps to Take

Users are advised to apply security updates provided by the vendor to mitigate the vulnerability and prevent exploitation.

Long-Term Security Practices

Implementing secure coding practices, regular security updates, and monitoring system activity can help prevent similar vulnerabilities in the future.

Patching and Updates

Vendors such as Red Hat have released security updates to address CVE-2021-3527. Regularly updating QEMU to the latest version will help protect systems from potential exploitation.