CVE-2020-29480 : What You Need to Know

An issue was discovered in Xen through 4.14.x where a guest administrator can observe non-sensitive domain and device lifecycle events relating to other guests, potentially revealing system configuration details.

Understanding CVE-2020-29480

This CVE highlights a vulnerability in Xen that allows a guest administrator to access information about other virtual machines and their configurations.

What is CVE-2020-29480?

The vulnerability in Xen through version 4.14.x allows a guest administrator to watch the root xenstored node without permission checks, leading to notifications for various key events and potentially exposing system configuration details of other guests.

The Impact of CVE-2020-29480

Guest administrators can access non-sensitive domain and device lifecycle events of other guests.
Information obtained includes VM numbers, types, and domids, driver domains, virtual interfaces, block devices, VCPUs, and more.
The exposed data may aid in understanding the system's overall configuration and that of other guests, potentially facilitating further attacks.

Technical Details of CVE-2020-29480

This section provides more in-depth technical insights into the vulnerability.

Vulnerability Description

Xenstore implementation lacks permission checks for reporting watch events, allowing unauthorized access.
Guest administrators can monitor key events without restrictions, potentially compromising system details.

Affected Systems and Versions

Xen through version 4.14.x is affected by this vulnerability.

Exploitation Mechanism

Guest administrators can exploit the lack of permission checks to watch xenstored nodes and receive notifications on various key events.

Mitigation and Prevention

Protecting systems from CVE-2020-29480 requires immediate actions and long-term security practices.

Immediate Steps to Take

Apply patches provided by Xen to address the vulnerability.
Monitor system logs for any suspicious activities.
Restrict guest administrator privileges to minimize exposure.

Long-Term Security Practices

Regularly update Xen and other software components to mitigate potential vulnerabilities.
Implement network segmentation to limit the impact of compromised guest accounts.

Patching and Updates

Stay informed about security advisories from Xen and promptly apply patches to secure the system.