CVE-2021-38917
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 · uneditedIBM PowerVM Hypervisor FW860, FW940, and FW950 could allow an attacker that gains service access to the FSP can read and write arbitrary host system memory through a series of carefully crafted service procedures. IBM X-Force ID: 210018.
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 confidenceIBM PowerVM Hypervisor firmware versions FW860, FW940, and FW950 contain a vulnerability in the Flexible Service Processor (FSP) that allows an authenticated attacker with service access to read and write arbitrary host system memory through crafted service procedures, enabling potential complete system compromise.
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= fw860= fw940= fw950CVSS 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
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
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 PowerVM Hypervisor firmware versionAccess the Hardware Management Console (HMC) and navigate to the system properties, or use the 'lsfwinfo' or 'lsmcode' command via HMC CLI to retrieve the current FSP firmware level.Affected if The displayed firmware version matches exactly FW860, FW940, or FW950.
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Confirm FSP service interface accessibilityVerify whether the Flexible Service Processor service interface is network-accessible, typically via the HMC or directly to the FSP. Check if TCP/IP ports for FSP service (such as port 22 for SSH or port 657 for IMM/FSP communication) are open and reachable from any network segment beyond the management network.Affected if The FSP service interface is accessible from a network where unauthorized or untrusted users could obtain authentication credentials.
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Review FSP service user accountsExamine the list of users and service accounts authorized to access the FSP service functions. Use HMC user management interfaces or the 'mkvterm' and 'lsuser' commands to list accounts with service or higher privileges.Affected if Any service account credentials are shared beyond strictly limited authorized personnel, or if default/service accounts use weak or default passwords.
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Check for unauthorized FSP command executionReview FSP and HMC audit logs for any execution of low-level service procedures, particularly memory read/write operations or hardware configuration changes. Look for commands such as 'fspcmds' or privilege-escalated service operations in system logs.Affected if Evidence exists of memory manipulation commands or suspicious service procedures having been executed on the FSP.
You are affected if your PowerVM Hypervisor runs firmware version FW860, FW940, or FW950 and the FSP service interface is accessible to any authenticated user beyond trusted administrators.
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 dataApply IBM firmware updates (FW860, FW940, FW950 patches) as provided by IBM. Restrict FSP service access to authorized personnel only and ensure proper network segmentation of management interfaces.
- Consultation6.0 h
- Implementation12.0 h
- Testing6.0 h
- Review / QA3.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $7,680.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-38917 — 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-2021-38917 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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A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- 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
- No spam, self-promotion, credentials, or personal data