CVE-2021-28123Network attack vector

Superuser access via undocumented default SSH key

Published Apr 2, 2021 · Updated Aug 3, 2024

Incorrect access control in affected Cohesity DataPlatform 6.3, 6.4, and 6.5.1 releases allows remote attackers to gain superuser Linux access via SSH. The SSH access component retains an undocumented default cryptographic key and accepts it for privileged authentication. Network access to the cluster SSH service is sufficient, and successful use grants superuser access to the cluster Linux interface.

CVSS severity9.8
Critical
EPSS probability1.43%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Incorrect access control in affected Cohesity DataPlatform 6.3, 6.4, and 6.5.1 releases allows remote attackers to gain superuser Linux access via SSH. The SSH access component retains an undocumented default cryptographic key and accepts it for privileged authentication. Network access to the cluster SSH service is sufficient, and successful use grants superuser access to the cluster Linux interface.

The record

CVE
CVE-2021-28123
Published
Apr 2, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-1188, T1078.001
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 2, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.5NIST NVDAV:N/AC:L/Au:N/C:P/I:P/A:P
9.8CohesityCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.8NIST NVDCVSS: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-1188Initialization of a Resource with an Insecure Default
T1078.001Valid Accounts: Default 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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo