CVE-2017-12136 Explained : Impact and Mitigation

Xen versions 4.6.x through 4.9.x are vulnerable to a race condition in the grant table code, potentially allowing local administrators of guest OS to disrupt the free list, crash the host, and gain unauthorized privileges.

Understanding CVE-2017-12136

What is CVE-2017-12136?

The vulnerability in Xen versions 4.6.x through 4.9.x exposes a race condition that can be exploited by local administrators of guest OS to disrupt the free list, crash the host, and gain unauthorized privileges.

The Impact of CVE-2017-12136

The exploit can lead to a denial of service by disrupting the free list or crashing the host. Additionally, it can result in unauthorized privilege escalation on the host.

Technical Details of CVE-2017-12136

Vulnerability Description

The vulnerability arises from a race condition in the grant table code of Xen versions 4.6.x through 4.9.x, allowing local guest OS administrators to cause denial of service or gain host privileges through maptrack free list handling.

Affected Systems and Versions

Product: Not applicable
Vendor: Not applicable
Versions affected: 4.6.x through 4.9.x

Exploitation Mechanism

The exploit involves the handling of maptrack free list, enabling local administrators of guest OS to disrupt the free list, crash the host, and potentially gain unauthorized privileges.

Mitigation and Prevention

Immediate Steps to Take

Apply patches provided by Xen to address the vulnerability.
Monitor Xen security advisories for updates and apply them promptly.

Long-Term Security Practices

Regularly update Xen software to the latest stable versions.
Implement the principle of least privilege to restrict access and limit potential damage.
Conduct regular security audits and assessments to identify and mitigate vulnerabilities.

Patching and Updates

Xen has released patches to address the vulnerability. Ensure all affected systems are updated with the latest patches to mitigate the risk of exploitation.