Security readout for executives and security teams
Plain-English summary
CVE-2020-5355 lets certain low-privileged Dell Isilon OneFS SSH users get more network forwarding access than intended. It does not describe full system takeover, but it can weaken access controls around storage infrastructure and expose information paths that should have been restricted.
Executive priority
Treat this as a moderate storage-platform access-control issue. Prioritize environments where Isilon SSH is reachable beyond tightly controlled admin networks or where shared support accounts exist.
Technical view
Dell Isilon OneFS 8.2.2 and earlier improperly permits TCP and stream forwarding in the SSHD process for the remotesupport user and users assigned restricted shells. CVSS 3.1 is 4.3: network reachable, low complexity, low privileges required, no user interaction, and limited confidentiality impact.
Likely exposure
Exposure is limited to Dell Isilon OneFS deployments running version 8.2.2 or earlier, especially where SSH access exists for remotesupport or restricted-shell users.
Exploitation context
The sources do not show CISA KEV listing or active exploitation. Abuse requires an authenticated low-privileged SSH-capable account, so insider, compromised account, or support-access scenarios matter most.
Researcher notes
Evidence is narrow: the public bundle names the vulnerable component and access-control impact but does not include exploit details, fixed versions, or concrete workarounds. Avoid assuming broader OneFS versions or active exploitation without Dell advisory confirmation.
Mitigation direction
- Check Dell advisory KB 543561 for official fixes or workarounds.
- Inventory OneFS clusters and identify versions 8.2.2 or earlier.
- Upgrade or remediate affected OneFS systems according to Dell guidance.
- Review whether remotesupport and restricted-shell SSH access is still required.
- Limit SSH access paths to trusted administrative networks where feasible.
Validation and detection
- Confirm each Isilon OneFS cluster version and compare against 8.2.2 or earlier.
- Review accounts using remotesupport or restricted shells.
- Verify vendor remediation is applied on affected clusters.
- Check SSH configuration against Dell-supported guidance for forwarding restrictions.
- Review logs for unexpected SSH activity by restricted or support accounts.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
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ATT&CK lookup starting points
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CWE-276: Exact CWE lookup
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Open ATT&CK lookupCVE-2020-5355 mapping review
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Open ATT&CK lookup- Severity
- Medium
- CVSS
- 4.3 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
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.
CVSS vector scores
1 official scoreWe 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.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N2.81.4Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
4.3MediumVector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://support.emc.com/kb/543561CVE reference
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Incorrect Default Permissions
Incorrect Default Permissions represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.