CVE-2021-21488
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 · uneditedKnowledge Management versions 7.01, 7.02, 7.30, 7.31, 7.40, 7.50 allows a remote attacker with basic privileges to deserialize user-controlled data without verification, leading to insecure deserialization which triggers the attacker’s code, therefore impacting Availability.
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 confidenceInsecure deserialization vulnerability in SAP Knowledge Management versions 7.01-7.50 allows an authenticated attacker with basic privileges to deserialize malicious user-controlled data without validation, enabling arbitrary code execution that primarily impacts system availability.
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= 7.01= 7.02= 7.30= 7.31= 7.40= 7.50CVSS 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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Identify SAP NetWeaver Knowledge Management versionCheck the installed SAP NetWeaver version and confirm the Knowledge Management (KM) component version by querying the SAP system information (via SAPMMC, SAP NetWeaver Administrator, or system report). Compare the KM version against the affected range: 7.01, 7.02, 7.30, 7.31, 7.40, 7.50.Affected if The installed KM version matches exactly one of these: 7.01, 7.02, 7.30, 7.31, 7.40, or 7.50.
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Verify KM service is enabled and exposedConfirm that Knowledge Management services are enabled in the SAP NetWeaver system. Check the ICM (Internet Communication Manager) or Web Dispatcher configuration to determine if KM-related HTTP/HTTPS endpoints are exposed to the network.Affected if KM services are enabled and accessible over the network (especially untrusted networks).
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Confirm basic authentication is available for KMVerify that the affected system allows basic (or any form of) authentication for Knowledge Management endpoints. Check the UM (User Management) and KM security configuration to confirm user authentication is active for the affected KM functions.Affected if Basic user authentication is enabled for KM services, allowing an authenticated attacker with basic privileges to access the vulnerable deserialization point.
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Inspect KM deserialization configurationReview the SAP KM configuration for any custom serializers or data transformation components. Check if the system accepts serialized Java objects through KM upload, transfer, or indexing features.Affected if The KM configuration allows deserialization of user-controlled data without additional validation layers.
A user is affected if their SAP NetWeaver Knowledge Management is version 7.01, 7.02, 7.30, 7.31, 7.40, or 7.50 and the KM services are network-accessible with authentication enabled.
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 SAP security patches for CVE-2021-21488 when available; until then, restrict network access to KM services and monitor for deserialization-based attack patterns.
- 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-2021-21488 — 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-2021-21488 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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