CVE-2021-26581
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 · uneditedA potential security vulnerability has been identified in HPE Superdome Flex server. A denial of service attack can be remotely exploited leaving hung connections to the BMC web interface. The monarch BMC must be rebooted to recover from this situation. Other BMC management is not impacted. HPE has made the following software update to resolve the vulnerability in HPE Superdome Flex Server: Superdome Flex Server Firmware 3.30.142 or later.
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 · high confidenceA remote denial of service vulnerability in HPE Superdome Flex server's monarch BMC web interface allows attackers to cause hung connections, rendering the BMC inaccessible. Recovery requires a physical reboot of the monarch BMC, while other BMC management functions remain unaffected.
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< 3.30.142CVSS 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
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/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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Confirm HPE Superdome Flex Server modelCheck system model via iLO or physical server label - look for 'Superdome Flex' in product nameAffected if System is not an HPE Superdome Flex Server, this CVE does not apply
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Identify installed firmware versionAccess the BMC web interface (iLO) or use hponcfg/ilorest CLI tools to query the firmware version. Look for the System ROM or BMC firmware version string in the firmware inventoryAffected if Firmware version cannot be determined or is not visible in BMC inventory
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Compare version to affected rangeCompare your installed firmware version number to 3.30.142 - versions below 3.30.142 are affectedAffected if Installed firmware version is 3.30.142 or higher, the vulnerability is patched
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Verify BMC web interface is accessibleCheck if the BMC web interface (port 443 or 80 on the BMC IP) is reachable from network. Confirm web service is enabled in BMC settingsAffected if BMC web interface is disabled and not network-accessible, the attack surface may be reduced (though firmware update is still recommended)
System is affected if it is an HPE Superdome Flex Server with firmware version below 3.30.142 and the BMC web interface is network-accessible, allowing remote attackers to cause hung BMC connections.
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.
From vendor data3.30.142
Upgrade HPE Superdome Flex Server firmware to version 3.30.142 or later to resolve the vulnerability.
- Consultation4.0 h
- Implementation6.0 h
- Testing3.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-26581 — 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-2021-26581 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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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
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