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CVE Record

CVE-2021-36305: Dell PowerScale OneFS contains an Unsynchronized Access to Shared Data in a Multithreaded Context in SMB CA...

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.

MediumCVSS 6.5Not KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

This vulnerability can let an authenticated SMB user disrupt SMB availability on affected Dell PowerScale OneFS clusters when Continuous Availability is enabled. It is not a data theft or data modification issue based on the CVSS vector, but it can affect business access to file services.

Executive priority

Treat this as a moderate operational resilience issue. It is unlikely to justify emergency response without business-critical SMB exposure, but affected production storage clusters should be prioritized in normal patch and maintenance planning.

Technical view

CVE-2021-36305 is an unsynchronized shared-data access issue in multithreaded SMB Continuous Availability handling in Dell PowerScale OneFS. The CVSS 3.1 vector is AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H, meaning network access and low privileges are required, with high availability impact only.

Likely exposure

Exposure is most relevant for organizations running Dell PowerScale OneFS versions 8.2.0, 8.2.1, 8.2.2, 9.0.0.x, 9.1.0.x, 9.1.1.x, 9.2.0.x, or 9.2.1.x with SMB Continuous Availability enabled.

Exploitation context

The source bundle does not show active exploitation, and KEV status is false. Exploitation requires an authenticated SMB user on a cluster with Continuous Availability, so risk depends heavily on SMB user access controls and whether CA is enabled.

Researcher notes

Evidence supports an authenticated, network-reachable denial-of-service condition in SMB CA handling. Public source details are limited; the Dell advisory is the key source for exact remediation guidance. No exploit procedure or active exploitation claim is supported by the provided sources.

Mitigation direction

  • Review Dell advisory 000192046 for vendor-recommended remediation and fixed builds.
  • Prioritize clusters running SMB with Continuous Availability enabled.
  • Restrict SMB access to trusted users and networks while remediation is planned.
  • Monitor SMB availability, cluster health, and denial-of-service symptoms.
  • Coordinate maintenance because remediation may require OneFS cluster updates.

Validation and detection

  • Inventory PowerScale clusters and record current OneFS versions.
  • Confirm whether SMB Continuous Availability is enabled on each cluster.
  • Review SMB authentication scope and identify low-privilege users with access.
  • Check monitoring for repeated SMB service disruption or availability degradation.
  • Map affected versions against Dell advisory guidance before remediation.
Prepared
Confidence
medium
Sources
3

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

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CVE-2021-36305 mapping review

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Vulnerability profileCVE Program record
Severity
Medium
CVSS
6.5 (3.1)
Known Exploited
No
Published

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

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

1CVSS vectors
0Timeline events
0ADP providers
2Source links

CVSS vector scores

1 official score

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
6.5CVSS 3.1MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H2.83.6Primary CVE score

Vulnerability scoring details

Base CVSS 3.1 score

6.5Medium
CVSS 3.1 vector shape for CVE-2021-36305Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

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

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
DellPowerScale OneFS8.2.0, 8.2.1, 9.0.0.x, 9.2.0.x, 9.1.1.x, 8.2.2, 9.1.0.x , 9.2.1.xListed
Weakness

CWE details

No CWE listed

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