CVE-2023-20900 : What You Need to Know

This CVE-2023-20900 was published on August 31, 2023, by VMware. It involves a vulnerability in VMware Tools that can be exploited by a malicious actor to elevate their privileges on a target virtual machine.

Understanding CVE-2023-20900

This section dives into the details of the CVE-2023-20900 vulnerability, its impact, technical aspects, and mitigation strategies.

What is CVE-2023-20900?

The vulnerability allows a malicious actor with Guest Operation Privileges in a target virtual machine to escalate their privileges if the virtual machine has a more privileged Guest Alias assigned to it. This privilege escalation can lead to severe consequences.

The Impact of CVE-2023-20900

The impact of this vulnerability is rated as high, with a CVSS v3.1 base score of 7.1. The attack complexity is high, and the confidentiality, integrity, and availability impacts are all rated as high. Privileges required for exploitation are low, making it a significant security concern.

Technical Details of CVE-2023-20900

This section provides more technical insights into the vulnerability, its description, affected systems and versions, and the exploitation mechanism.

Vulnerability Description

The vulnerability stems from a SAML Token Signature Bypass vulnerability within VMware Tools, which can be abused to elevate privileges in a virtual machine.

Affected Systems and Versions

Windows platform:
VMware Tools versions 12.x.x, 11.x.x, and 10.3.x are affected.
Linux platform:
VMware Tools version 10.3.x and VMware Tools (open-vm-tools) versions 12.x.x, 11.x.x, and 10.3.x are affected.

Exploitation Mechanism

A malicious actor with Guest Operation Privileges in a target virtual machine can exploit the vulnerability by leveraging a more privileged Guest Alias assigned to the virtual machine.

Mitigation and Prevention

To safeguard systems from CVE-2023-20900, immediate actions should be taken along with the implementation of long-term security practices.

Immediate Steps to Take

Update VMware Tools to the latest patched version.
Monitor and restrict Guest Alias privileges in virtual machines.
Implement network segmentation to limit the impact of potential privilege escalation.

Long-Term Security Practices

Regularly audit and review user privileges and access levels.
Conduct security training for users on identifying and reporting unusual activities.
Stay informed about security advisories and patches released by VMware.

Patching and Updates

Refer to VMware's security advisory (VMSA-2023-0019) for specific patching instructions and guidelines to address CVE-2023-20900. Regularly update VMware Tools to mitigate known vulnerabilities and enhance system security.