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Netweaver As AbapApplication · Sap

CVE-2021-27607

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 (Dispatcher), versions - KRNL32NUC - 7.22,7.22EXT, KRNL32UC - 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 - 7.22,8.04,7.49,7.53,7.73,7.77,7.81,7.82,7.83, 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 ThSncIn() 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

This is a denial-of-service vulnerability in SAP NetWeaver ABAP Server and ABAP Platform Dispatcher. An unauthenticated attacker can send a specially crafted packet over the network that triggers improper input validation in the ThSncIn() method, causing the system to crash and become unavailable. No data can be viewed or modified by the attacker.

MitigationApply the relevant SAP security patch for this vulnerability. As a temporary measure, restrict network access to the Dispatcher port using firewalls or network segmentation to limit exposure to unauthenticated attackers.

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= krnl32uc_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
    Use transaction SM37 or execute 'disp+work -v' at OS level to display the SAP kernel version. Alternatively, check via SAP LMDB (Landscape Management Database) or SAP Solution Manager.
    Affected if The kernel version matches any of the following: 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, or krnl32uc_7.22
  2. Confirm the system is an ABAP server with Dispatcher
    Verify that the SAP instance runs the ABAP message server and Dispatcher (disp+work process). Use transaction SM51 to list active application servers or check for the disp+work process at OS level.
    Affected if The system runs SAP NetWeaver ABAP Server or ABAP Platform with an active Dispatcher process (disp+work).
  3. Verify network exposure of the Dispatcher port
    Check which ports the Dispatcher is listening on (typically 32<instance> TCP). Use netstat -an | grep 32 or check the instance profile parameter rdisp/btcname. Verify if these ports are accessible from untrusted networks.
    Affected if The Dispatcher port is exposed to untrusted or external networks without firewall protection.
  4. Review instance profile for ThSncIn-related parameters
    Check the ABAP instance profile for parameters related to the ThSncIn method. Review profile parameters in transaction RZ11 or the default.PFL and instance profile files.
    Affected if The system uses default or minimal hardening of input validation parameters for the ThSncIn function.

You are affected if your SAP NetWeaver ABAP kernel version matches one of the listed affected versions AND the Dispatcher service is network-accessible to unauthenticated users.

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 relevant SAP security patch for this vulnerability. As a temporary measure, restrict network access to the Dispatcher port using firewalls or network segmentation to limit exposure to unauthenticated attackers.

Fix this in Netweaver As Abap Scoped from the published advisory
  • Consultation4.0 h
  • Implementation6.0 h
  • Testing8.0 h
  • Review / QA2.0 h
20.0 hours of engineering $3,440
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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-2021-27607 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