CVE-2021-28713 : Security Advisory and Response

A detailed overview of CVE-2021-28713 focusing on the impact, technical details, and mitigation steps.

Understanding CVE-2021-28713

In this section, we will dive into the key aspects of the CVE-2021-28713 vulnerability affecting Xen.

What is CVE-2021-28713?

The vulnerability allows rogue backends to cause Denial of Service (DoS) attacks on guests through high-frequency events. Three specific backends are affected.

The Impact of CVE-2021-28713

Potentially malicious PV backends can trigger guest DoS by exploiting unhardened frontends, despite being contained within a less privileged environment.

Technical Details of CVE-2021-28713

This section will cover the technical aspects of the CVE-2021-28713 vulnerability.

Vulnerability Description

The vulnerability stems from running PV backends in driver domains, where a compromised backend can generate high-frequency events causing DoS.

Affected Systems and Versions

Systems running Xen with specific affected backends - blkfront, netfront, and hvc_xen (console) are vulnerable.

Exploitation Mechanism

Malicious driver domains can initiate high-frequency events targeting other guests, leading to a DoS due to interrupt overload.

Mitigation and Prevention

Learn about the steps to mitigate and prevent CVE-2021-28713 in this section.

Immediate Steps to Take

As there is no known mitigation available, it is crucial to monitor for any unusual activity.

Long-Term Security Practices

Implement strict monitoring protocols, audit trail systems, and regularly update the security measures to prevent DoS attacks.

Patching and Updates

Stay informed about security advisories from Xen and related vendors to apply necessary patches and updates in a timely manner.