CVE-2023-20896Public exploitNetwork attack vector

Service crashes via unchecked DCERPC presentation-list offset

Published Jun 22, 2023 · Updated Feb 13, 2025

Out-of-bounds read in VMware vCenter Server 7.0 before 7.0 U3m and 8.0 before 8.0 U1b allows remote attackers to crash DCERPC services. The DCERPC unpack_port_any routine adds an attacker-controlled 16-bit length to a packet pointer without checking the receive-buffer boundary, and unpack_pres_result_list then dereferences the resulting pointer. The affected services listen without authentication on local-network ports 2012, 2014, and 2020, including when vCenter Server is bundled with Cloud Foundation.

CVSS severity5.9
Medium
EPSS probability0.91%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds read in VMware vCenter Server 7.0 before 7.0 U3m and 8.0 before 8.0 U1b allows remote attackers to crash DCERPC services. The DCERPC unpack_port_any routine adds an attacker-controlled 16-bit length to a packet pointer without checking the receive-buffer boundary, and unpack_pres_result_list then dereferences the resulting pointer. The affected services listen without authentication on local-network ports 2012, 2014, and 2020, including when vCenter Server is bundled with Cloud Foundation.

The record

CVE
CVE-2023-20896
Published
Jun 22, 2023
Updated
Feb 13, 2025
Vendor
VMware
Product
VMware vCenter Server
Classifications
CWE-823, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 22, 2023CVE publishedPublication date reported by the CVE source.
  2. Feb 13, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=7.0 <7.0 u3m
  2. Affected versionversion=8.0 <8.0 U1b

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

VMware · VMware vCenter Serverversion=7.0 <7.0 u3m; version=8.0 <8.0 U1b
VMware · VMware Cloud Foundationversion=4.x <7.0 U3m, 8.0 U1b; version=5.x <7.0 U3m, 8.0 U1b

Published CVSS scores

7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
5.9VMwareCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-823Use of Out-of-range Pointer Offset
T1499.004Application or System Exploitation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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