Mitigation Instructions for CVE-2023-34048

SUBJECT: Critical Out-of-Bounds Write Vulnerability in VMware vCenter Server (CVE-2023-34048)

TECH STACK: VMware vCenter Server versions 4.0 through 8.0 (all updates and sub-versions included) 

DATE(S) ISSUED: 10/25/2023

NVD Last Modified: 01/22/2024

CRITICALITY: CRITICAL (CVSS v3 Base Score: 9.8)

OVERVIEW: 

CVE-2023-34048 is a critical out-of-bounds write vulnerability in the DCERPC protocol implementation of VMware vCenter Server. 

This vulnerability allows a malicious actor with network access to vCenter Server to potentially trigger an out-of-bounds write, leading to remote code execution and complete control over the affected system.

SOLUTION: 

• Immediate Action:

  • Apply applicable security updates: Update all affected vCenter Server deployments to the latest patched versions as soon as possible. Refer to the VMware Security Advisory VMSA-2023-0023 for specific patch versions: https://docs.vmware.com/en/VMware-vSphere/7.0/rn/vsphere-vcenter-server-70u3l-release-notes.html
  • Restrict network access: Limit network access to vCenter Server to authorized personnel and systems only. Implement network segmentation and access control measures to further restrict access to the vulnerable service.

  Additional Recommendations:

  • Monitor for exploit attempts: Actively monitor your systems for signs of suspicious activity that could indicate exploitation attempts.
  • Maintain backups: Regularly back up your vCenter Server systems to ensure you can recover from a potential attack.
  • Implement security best practices: Follow general security best practices, such as using strong passwords, keeping software updated, and implementing security awareness training for users.

  REFERENCES:

  Third Party Advisories:

  1. NVD Entry
  2. VMware Security Advisory VMSA-2023-0023 CISA Known Exploited Vulnerabilities Catalog

  Confirmation & Additional Information:

  1. This vulnerability affects all versions of VMware vCenter Server from 4.0 through 8.0, including all updates and sub-versions.
  2. CVE-2023-34048 has been classified as CRITICAL with a CVSS v3 base score of 9.8, indicating a severe risk of exploitation.
  3. This vulnerability is actively exploited by malicious actors, as listed in CISA's Known Exploited Vulnerabilities Catalog.
  4. Exploitation Vectors: The vulnerability can be exploited remotely by a malicious actor with network access to vCenter Server. No user interaction is required.
  5. Potential Impact: Successful exploitation could allow attackers to gain complete control over the affected vCenter Server, including the ability to execute arbitrary code, steal data, and disrupt operations.
  6. Urgency: Immediate action is required to patch vulnerable systems and implement additional security measures.