CVE-2021-33684
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 · uneditedSAP NetWeaver AS ABAP and ABAP Platform, versions - KRNL32NUC 7.21, 7.21EXT, 7.22, 7.22EXT, KRNL32UC 7.21, 7.21EXT, 7.22, 7.22EXT, KRNL64NUC 7.21, 7.21EXT, 7.22, 7.22EXT, 7.49, KRNL64UC 8.04, 7.21, 7.21EXT, 7.22, 7.22EXT, 7.49, 7.53, KERNEL 8.04, 7.21, 7.21EXT, 7.22, 7.22EXT, 7.49, 7.53, 7.77, 7.81, 7.84, allows an attacker to send overlong content in the RFC request type thereby crashing the corresponding work process because of memory corruption vulnerability. The work process will attempt to restart itself after the crash and hence the impact on the availability is low.
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 confidenceIn SAP NetWeaver AS ABAP, the RFC (Remote Function Call) request handler fails to properly validate input length when processing RFC request types. An attacker sending overlong content in an RFC request triggers memory corruption, causing the associated work process to crash. The work process automatically restarts after the crash, limiting availability impact.
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= 7.21= 7.21ext= 7.22= 7.22ext= 7.49= 7.53= 7.77= 7.81= kernel_8.04= krnl32nuc_7.21= krnl32uc_7.21= krnl64nuc_7.21= 7.21= 7.21ext= 7.22= 7.22ext= 7.49= 7.53= 7.77= 7.81= kernel_8.04= krnl32nuc_7.21= krnl32uc_7.21= krnl64nuc_7.21CVSS 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
- None
- Integrity
- None
- Availability
- Low
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
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 ABAP versionAccess transaction SM51 (SAP System) or execute SAP kernel version check command; review the kernel patch level in system informationAffected if The installed kernel version matches 7.21, 7.21ext, 7.22, 7.22ext, 7.49, 7.53, 7.77, 7.81, kernel_8.04, krnl32nuc_7.21, krnl32uc_7.21, or krnl64nuc_7.21 without subsequent security patches applied
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Confirm RFC functionality is activeAccess transaction SM59 to view configured RFC destinations, or check transaction SM37 for work process activity; verify that RFC listener processes are runningAffected if RFC request handling is enabled and exposed, as the vulnerability exists in the RFC request handler component
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Inspect work process logs for crashesReview transaction SM21 (System Log) or transaction ST03 for recent work process terminations; filter for error codes related to memory corruption or ABAP runtime errorsAffected if Work process crashes are logged with symptoms of memory corruption or abnormal termination following RFC request processing
You are affected if your SAP NetWeaver ABAP kernel version is among the listed unpatched versions AND RFC functionality is enabled and accessible in your environment.
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 the relevant SAP kernel patch for CVE-2021-33684. Until patches are available, consider restricting RFC access via network-level controls or SAP authorization restrictions to reduce attack surface.
- Consultation4.0 h
- Implementation8.0 h
- Testing8.0 h
- Review / QA4.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $6,656.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-33684 — 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-2021-33684 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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