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Emc Powerscale OnefsOperating system · Dell

CVE-2021-36305

MEDIUM · 6.5 CVSS v3.1 Published 2021-11-12
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
71/100
Remediation priority · Elevated
Remotely reachable Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Dell PowerScale OneFS contains an Unsynchronized Access to Shared Data in a Multithreaded Context in SMB CA handling. An authenticated user of SMB on a cluster with CA could potentially exploit this vulnerability, leading to a denial of service over SMB.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Dell PowerScale OneFS contains a race condition vulnerability in the SMB Continuous Availability (CA) feature where unsynchronized access to shared data in a multithreaded context can lead to corruption or denial of service. An authenticated SMB user on a cluster with CA enabled can trigger this condition, causing the SMB service to become unavailable.

MitigationApply the vendor-supplied patch from Dell for PowerScale OneFS that addresses the unsynchronized access issue in SMB CA handling. Ensure SMB CA functionality is tested after patching.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Emc Powerscale OnefsOperating system
Affected:= 8.2.0= 8.2.1= 8.2.2= 9.0.0.0= 9.1.0.0= 9.1.1.0= 9.2.0.0= 9.2.1.0

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify the PowerScale OneFS version
    Run the command to display the OneFS version (such as 'isi version' or check the system interface for the firmware version)
    Affected if The installed version matches 8.2.0, 8.2.1, 8.2.2, 9.0.0.0, 9.1.0.0, 9.1.1.0, 9.2.0.0, or 9.2.1.0
  2. Determine if SMB Continuous Availability is enabled
    Check the SMB configuration to see if the CA feature is turned on for any shares or globally (typically via 'isi smb' commands or through the web administration interface)
    Affected if SMB CA is enabled on the cluster, making the race condition exploitable
  3. Verify SMB service accessibility
    Attempt to access an SMB share or check the SMB service status to confirm the service is currently running
    Affected if SMB service is running and accessible, which is required for an authenticated user to trigger the vulnerability
  4. Confirm user authentication capability
    Verify that SMB user authentication is configured and functional on the cluster
    Affected if SMB users can authenticate to the cluster, which is required to exploit this vulnerability as described

The environment is affected only if the PowerScale OneFS version is one of the listed affected versions AND SMB Continuous Availability is enabled, allowing an authenticated SMB user to trigger the race condition.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply the vendor-supplied patch from Dell for PowerScale OneFS that addresses the unsynchronized access issue in SMB CA handling. Ensure SMB CA functionality is tested after patching.

Recommended fix Moderate confidence

OneFS 9.5.0.0 or later (specific fixed release available from Dell support)

  1. 1. Identify the current OneFS version by running 'isi version' or checking the cluster management interface
  2. 2. Review the Dell PowerScale OneFS compatibility and upgrade guide at www.dell.com/support
  3. 3. Schedule a maintenance window for the upgrade, ensuring proper backups are in place
  4. 4. Download the recommended OneFS 9.5.0.0 or later patch from Dell Support portal
  5. 5. Apply the upgrade following Dell's documented upgrade procedure for PowerScale OneFS
  6. 6. Verify the fix by confirming the OneFS version post-upgrade: 'isi version'
  7. 7. Test SMB CA functionality to ensure the vulnerability is remediated and services are operational
Caveat Review Dell upgrade documentation for any configuration changes or migration considerations between major versions; test in non-production environment first

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Emc Powerscale Onefs Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA1.0 h
10.0 hours of engineering $1,750
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2021-36305 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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