CVE-2021-27797
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedBrocade Fabric OS before Brocade Fabric OS v8.2.1c, v8.1.2h, and all versions of Brocade Fabric OS v8.0.x and v7.x contain documented hard-coded credentials, which could allow attackers to gain access to the system.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · moderate confidenceBrocade Fabric OS contains documented hard-coded credentials embedded in the firmware across multiple versions (v7.x, v8.0.x, and vulnerable releases before v8.2.1c/v8.1.2h). These default credentials allow remote attackers to bypass authentication and gain unauthorized administrative access to the fabric infrastructure.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data>= 7.0.0, <= 7.4.2h>= 8.0.0, <= 8.0.2f>= 8.1.2, < 8.1.2h>= 8.2.1, < 8.2.1cCVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify Fabric OS versionRun the 'version' command on the fabric switch CLI or check the firmware version in the admin web interface under System > FirmwareAffected if The installed version falls within 7.0.0 to 7.4.2h, 8.0.0 to 8.0.2f, 8.1.2 to 8.1.2g, or 8.2.1 to 8.2.1b
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Verify default admin credentialsLog into the switch using the default admin account and attempt to change the password. If the account responds to the documented default credentials (such as admin/admin or admin/password), the credentials have not been changed.Affected if The default administrative accounts still use factory-set credentials that have not been altered since deployment
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Check for unauthorized admin accountsList all administrative accounts on the fabric (using 'userconfig --show' or equivalent in the CLI) and audit for any unrecognized accounts that may indicate prior exploitation using the hard-coded credentials.Affected if Unexpected admin-level accounts exist that were not created by your organization
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Review authentication logsExamine the switch audit logs for successful logins from unexpected IP addresses or at unusual times, particularly via SSH, HTTP, or HTTPS management interfaces.Affected if Authentication events match known patterns of exploitation or originate from untrusted sources
The environment is affected if the Fabric OS version is within the vulnerable ranges AND default credentials have not been changed from factory settings.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped8.1.2h8.2.1c
Upgrade to Brocade Fabric OS v8.2.1c, v8.1.2h, or later versions. Immediately change any default credentials and audit for unauthorized access.
Upgrade to Fabric OS v8.2.1c or later, or v8.1.2h or later. Versions 7.x and 8.0.x are end-of-life with no fix; migrate to supported 8.1.x or 8.2.x branches.
- 1. Identify the current Fabric OS version by running 'version' or 'firmwareShow' command.
- 2. For versions 7.0.0-7.4.2h: These versions have no fix available; plan migration to a supported 8.x branch.
- 3. For versions 8.0.0-8.0.2f: These versions have no fix available; upgrade to 8.1.2h or 8.2.1c or later.
- 4. For versions 8.1.2 to 8.1.2g: Upgrade to version 8.1.2h or later.
- 5. For versions 8.2.1 to 8.2.1b: Upgrade to version 8.2.1c or later.
- 6. Download the appropriate firmware from Broadcom support portal (support.broadcom.com).
- 7. Upload and install the new firmware using 'firmwareDownload' command following standard FOS upgrade procedures.
- 8. After upgrade, verify the new version with 'version' command.
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation6.0 h
- Implementation12.0 h
- Testing6.0 h
- Review / QA3.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-27797 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2021-27797 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
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