---
title: "CVE-2023-34048: VMware vCenter Server Out-of-Bounds Write Vulnerability"
url: https://erroneo.us/security/cve/CVE-2023-34048/
description: "CVE-2023-34048 (VMware vCenter Server): Exploited in the wild (CISA KEV). vCenter Server contains an out-of-bounds write vulnerability in the implementation…"
type: vulnerability-record
section: "Security Digest"
date_published: 2023-10-25
date_modified: 2025-10-21
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2023-34048"
kev: true
cvss: 9.8
epss: 0.99428
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2023-34048: VMware vCenter Server Out-of-Bounds Write Vulnerability

**Signal:** Exploited: patch now if you run it. CISA has confirmed exploitation in the wild. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- Yes, if you run VMware vCenter Server. CISA added this CVE to its Known Exploited Vulnerabilities catalog on 2024-01-22, which means there is reliable evidence of exploitation in the wild. US federal agencies must remediate by 2024-02-12 ; treat that as the outer limit, not the target.
- EPSS 99.4% , percentile 99.9: FIRST’s model estimates a 99.4% chance of exploitation activity in the next 30 days, higher than 99.9% of all scored CVEs (very high). EPSS is a probability, not a verdict.
- Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.

## What it is

vCenter Server contains an out-of-bounds write vulnerability in the implementation of the DCERPC protocol. A malicious actor with network access to vCenter Server may trigger an out-of-bounds write potentially leading to remote code execution.

## Affected products (CVE record)

- VMware VMware vCenter Server: 8.0 < 8.0U2, 7.0 < 7.0U3o
- VMware VMware Cloud Foundation (VMware vCenter Server): 5.x, 4.x

## Severity

- vmware CVSS 3.1: 9.8 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`

## Exploitation

- CISA KEV: added 2024-01-22; federal due date 2024-02-12. Known ransomware use: Unknown.
- CISA required action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
- CISA SSVC assessment: exploitation active , automatable no , technical impact total .
- FIRST EPSS (model of 2026-10-21): 99.43% probability of exploitation activity in the next 30 days; percentile 99.9.

## Sources

- [Listed in CISA KEV notes (vmware.com)](https://www.vmware.com/security/advisories/VMSA-2023-0023.html)
- [CVE.org record CVE-2023-34048](https://www.cve.org/CVERecord?id=CVE-2023-34048)
- [NVD entry CVE-2023-34048](https://nvd.nist.gov/vuln/detail/CVE-2023-34048)
- [CISA Known Exploited Vulnerabilities catalog entry](https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-34048)
- [vicarius.io](https://www.vicarius.io/vsociety/posts/understanding-cve-2023-34048-a-zero-day-out-of-bound-write-in-vcenter-server)

---
Source page: https://erroneo.us/security/cve/CVE-2023-34048/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt