CVE-2021-21502Network attack vector

Expired-account SSH access via accepted public keys

Published Feb 9, 2021 · Updated Sep 16, 2024

Improper authentication in Dell PowerScale OneFS 8.1.0 through 9.1.0 allows remote attackers with expired accounts to retain SSH access. The SSH public-key authentication path accepts keys from expired accounts instead of enforcing account expiration before authorizing login. Exploitation requires an expired account that retains ISI_PRIV_LOGIN_SSH and possession of its authorized private key, restoring its pre-expiration access.

CVSS severity9.8
Critical
EPSS probability1.41%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper authentication in Dell PowerScale OneFS 8.1.0 through 9.1.0 allows remote attackers with expired accounts to retain SSH access. The SSH public-key authentication path accepts keys from expired accounts instead of enforcing account expiration before authorizing login. Exploitation requires an expired account that retains ISI_PRIV_LOGIN_SSH and possession of its authorized private key, restoring its pre-expiration access.

The record

CVE
CVE-2021-21502
Published
Feb 9, 2021
Updated
Sep 16, 2024
Vendor
Dell Technologies
Product
PowerScale OneFS
Classifications
CWE-287, T1078
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 9, 2021CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 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=unspecified <8.1.2 / 8.2.2 / 9.1.0.x / Empire / Main

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Dell Technologies · PowerScale OneFSversion=unspecified <8.1.2 / 8.2.2 / 9.1.0.x / Empire / Main

Published CVSS scores

9.8Dell TechnologiesCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-287Improper Authentication
T1078Valid Accounts

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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