What is CVE-2023-34048?

CVE-2023-34048 is a critical-severity vulnerability in VMware Vcenter Server, classified under Out-of-bounds Write. CVSS score: 9.8/10. Published 2023-10-25.

How severe is CVE-2023-34048?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Is CVE-2023-34048 known to be exploited?

Yes. CVE-2023-34048 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2024-01-22), indicating it is being actively exploited. 4 public proof-of-concept repositories are indexed.

Buffer overflow in VMware Vcenter Server

CVE-2023-34048

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.

Vulnerability class: Buffer Overflow

Published 2023-10-25 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.994 (99.9th percentile), scored 2026-10-15.

Very high probability of exploitation in the next 30 days — among the top 0.1% most-likely-to-be-exploited CVEs. 100th percentile — 99.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.994 · newest: 0.994 · change: 0.000

Affected products

VMware Vcenter Server — versions 7.0, 8.0
VMware Cloud Foundation (VMware Vcenter Server) — versions 5.x, 4.x
VMware Vcenter Server — versions 8.0, 7.0

Weakness classification (CWE)

CWE-787 — Out-of-bounds Write

CISA KEV (Known Exploited Vulnerabilities)

This CVE is on the CISA KEV catalog, added on 2024-01-22. CISA KEV inclusion means CISA has confirmed in-the-wild exploitation; US federal agencies are required to remediate within a published due date.

BOD 22-01 due date: 2024-02-12.

Required action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

Public proof-of-concept exploits

References

www.vmware.com/security/advisories/VMSA-2023-0023.html (Vendor Advisory)
af854a3a-2127-422b-91ae-364da2661108 (Exploit, Third Party Advisory)
134c704f-9b21-4f2e-91b3-4a467353bcc0 (US Government Resource)

Frequently asked questions

What is CVE-2023-34048?: CVE-2023-34048 is a critical-severity vulnerability in VMware Vcenter Server, classified under Out-of-bounds Write. CVSS score: 9.8/10. Published 2023-10-25.
How severe is CVE-2023-34048?: Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2023-34048 known to be exploited?: Yes. CVE-2023-34048 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2024-01-22), indicating it is being actively exploited. 4 public proof-of-concept repositories are indexed.