CVE-2021-27794

Account access via invalid password acceptance

Published Aug 12, 2021 · Updated Aug 3, 2024

Improper authentication in Brocade Fabric OS before 9.0.1a, 8.2.3a, and 7.4.2h allows attackers to access accounts via invalid passwords. The authentication component accepts an empty or otherwise invalid password for Telnet, SSH, and REST logins; Broadcom has not disclosed the underlying code locus or validation error. Reachability requires access to an enabled management interface, and a successful session receives the privileges assigned to the accepted login.

CVSS severity7.8
High
EPSS probability0.24%
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 Brocade Fabric OS before 9.0.1a, 8.2.3a, and 7.4.2h allows attackers to access accounts via invalid passwords. The authentication component accepts an empty or otherwise invalid password for Telnet, SSH, and REST logins; Broadcom has not disclosed the underlying code locus or validation error. Reachability requires access to an enabled management interface, and a successful session receives the privileges assigned to the accepted login.

The record

CVE
CVE-2021-27794
Published
Aug 12, 2021
Updated
Aug 3, 2024
Vendor
Brocade Communications Systems
Product
Brocade Fabric OS
Classifications
CWE-287, T1190
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 12, 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

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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=before Brocade Fabric OS v.9.0.1a, v8.2.3a and v7.4.2h

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Brocade Communications Systems · Brocade Fabric OSversion=before Brocade Fabric OS v.9.0.1a, v8.2.3a and v7.4.2h

Published CVSS scores

7.8BroadcomCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
4.6NISTAV:L/AC:L/Au:N/C:P/I:P/A:P
7.8NISTCVSS:3.1/AV:L/AC:L/PR:L/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)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-287Improper Authentication
T1190Exploit Public-Facing Application

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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