CVE-2021-38923Network attack vector

Peer VM access via duplicate WWPN assignment

Published Oct 6, 2021 · Updated Sep 17, 2024

Authentication bypass in IBM PowerVM Hypervisor FW1010 allows remote authenticated users to access another VM via duplicate WWPN assignment. The hypervisor can assign identical worldwide port names to virtual Fibre Channel adapters in peer VMs after a specific sequence of service actions, breaking partition isolation. A privileged user and the affected service-operation sequence are required; the resulting impact includes unauthorized access to another VM's resources.

CVSS severity8.0
High
EPSS probability1.06%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authentication bypass in IBM PowerVM Hypervisor FW1010 allows remote authenticated users to access another VM via duplicate WWPN assignment. The hypervisor can assign identical worldwide port names to virtual Fibre Channel adapters in peer VMs after a specific sequence of service actions, breaking partition isolation. A privileged user and the affected service-operation sequence are required; the resulting impact includes unauthorized access to another VM's resources.

The record

CVE
CVE-2021-38923
Published
Oct 6, 2021
Updated
Sep 17, 2024
Vendor
IBM
Product
PowerVM Hypervisor
Classifications
Unavailable
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Oct 6, 2021CVE publishedPublication date reported by the CVE source.
  2. Sep 17, 2024Record 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=FW1010

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

IBM · PowerVM Hypervisorversion=FW1010

Published CVSS scores

7.0NVD enrichment of IBM CNA recordCVSS:3.0/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H/E:U/RL:O/RC:C
8.0IBMCVSS:3.0/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/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
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

No sourced classifications are available.

Public exploit references

No public exploit references are available in this record.

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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