CVE-2020-25723 : Security Advisory and Response

A reachable assertion issue in the USB EHCI emulation code of QEMU could allow a malicious user to crash the QEMU process, leading to a denial of service.

Understanding CVE-2020-25723

This CVE involves a vulnerability in the USB EHCI emulation code of QEMU that could be exploited by a privileged user to crash the QEMU process on the host.

What is CVE-2020-25723?

This CVE describes a reachable assertion issue in the USB EHCI emulation code of QEMU, allowing a malicious user within the guest to crash the QEMU process on the host by sending bogus USB requests.

The Impact of CVE-2020-25723

The exploitation of this vulnerability could result in a denial of service (DoS) by crashing the QEMU process on the host system.

Technical Details of CVE-2020-25723

This section provides more technical insights into the vulnerability.

Vulnerability Description

The vulnerability arises due to missing handling of DMA memory map failure in the USB EHCI emulation code of QEMU, leading to a reachable assertion issue.

Affected Systems and Versions

Product: QEMU
Version: qemu 5.2.0

Exploitation Mechanism

A malicious privileged user within the guest can exploit this flaw by sending malicious USB requests, causing the QEMU process on the host to crash.

Mitigation and Prevention

Protecting systems from CVE-2020-25723 requires immediate actions and long-term security practices.

Immediate Steps to Take

Apply the necessary security updates provided by the vendor promptly.
Monitor and restrict USB traffic to prevent unauthorized access.

Long-Term Security Practices

Regularly update and patch software to address known vulnerabilities.
Implement least privilege access controls to limit the impact of potential exploits.
Conduct security assessments and audits to identify and mitigate risks.

Patching and Updates

Ensure that the affected QEMU version (qemu 5.2.0) is updated with the latest security patches to mitigate the vulnerability.