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Netweaver As AbapApplication · Sap

CVE-2021-27606

HIGH · 7.5 CVSS v3.1 Published 2021-06-09
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click

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 · unedited
SAP NetWeaver ABAP Server and ABAP Platform (Enqueue Server), versions - KRNL32NUC - 7.22,7.22EXT, KRNL64NUC - 7.22,7.22EXT,7.49, KRNL64UC - 8.04,7.22,7.22EXT,7.49,7.53,7.73, KERNEL - 7.22,8.04,7.49,7.53,7.73, allows an unauthenticated attacker without specific knowledge of the system to send a specially crafted packet over a network which will trigger an internal error in the system due to improper input validation in method EncOAMParamStore() causing the system to crash and rendering it unavailable. In this attack, no data in the system can be viewed or modified.

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 confidence

SAP NetWeaver ABAP Server and ABAP Platform Enqueue Server contains an improper input validation vulnerability in method EncOAMParamStore(). An unauthenticated attacker can send a specially crafted packet over the network that triggers an internal error and crashes the Enqueue Server, making the system unavailable. The attack requires no specific system knowledge and does not allow data exfiltration or modification.

MitigationApply the SAP security patches for CVE-2021-27606 to the affected kernel versions. This involves updating the SAP kernel to a patched version, which should be tested in non-production systems first, and scheduled during a maintenance window due to the critical nature of the Enqueue Server component.

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
Netweaver As AbapApplication
Affected:= kernel_7.22= kernel_7.49= kernel_7.53= kernel_7.73= kernel_7.77= kernel_7.81= kernel_7.82= kernel_7.83= kernel_8.04= krnl32nuc_7.22= krnl32nuc_7.22ext= krnl64nuc_7.22

CVSS 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
High

CVSS:3.1/AV:N/AC:L/PR:N/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 checks

Work through these to decide whether this CVE applies to you.

  1. Identify the SAP kernel version
    Execute command 'SAPCAR -tvf <kernel_archive> | grep SAPEXE' or check the 'kernel' directory in the SAP system for the 'disp+work' executable version. On Windows, check the version of disp+work.exe in the kernel directory. Use transaction SM51 to view the kernel release version displayed in the system.
    Affected if The installed kernel version matches 7.22, 7.49, 7.53, 7.73, 7.77, 7.81, 7.82, 7.83, or 8.04, or the kernel is identified as krnl32nuc_7.22, krnl32nuc_7.22ext, or krnl64nuc_7.22.
  2. Confirm Enqueue Server (ENSA) is active
    Use transaction SM37 to check for running work processes of type 'Enqueue'. Alternatively, use transaction SM51 to verify the 'Enqueue' service is listed. Check the profile parameter 'enque/serverhost' and 'enque/serverport' to identify the Enqueue Server instance.
    Affected if An Enqueue Server work process is running (type 'Enqueue' in SM37) or the Enqueue service is active in SM51.
  3. Verify the kernel patch level
    Execute transaction SM51 and note the kernel patch number shown (for example, 722 patch 100). Compare this to the base kernel version to determine if it is an unpatched release. Check the SAP Note referenced for CVE-2021-27606 to confirm the minimum patched version for your kernel release.
    Affected if The kernel patch level is lower than the patched version specified in SAP Note for CVE-2021-27606, or the kernel remains at the original unpatched release level.

The environment is affected if the installed SAP kernel version is one of the listed unpatched versions (7.22, 7.49, 7.53, 7.73, 7.77, 7.81, 7.82, 7.83, 8.04, or kernel types krnl32nuc_7.22/krnl32nuc_7.22ext/krnl64nuc_7.22) and the Enqueue Server component is active.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply the SAP security patches for CVE-2021-27606 to the affected kernel versions. This involves updating the SAP kernel to a patched version, which should be tested in non-production systems first, and scheduled during a maintenance window due to the critical nature of the Enqueue Server component.

Fix this in Netweaver As Abap Scoped from the published advisory
  • Consultation8.0 h
  • Implementation4.0 h
  • Testing16.0 h
  • Review / QA8.0 h
36.0 hours of engineering $6,160
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2021-27606 in production — separate from our analysis above.

No notes yet

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What this is

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.

What belongs here
  • 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