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Uncontrolled Resource ConsumptionWeakness · CWE-400

CVE-2024-43647

HIGH · 7.5 CVSS v3.1 Published 2024-09-10
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
A vulnerability has been identified in SIMATIC S7-200 SMART CPU CR40 (6ES7288-1CR40-0AA0) (All versions), SIMATIC S7-200 SMART CPU CR60 (6ES7288-1CR60-0AA0) (All versions), SIMATIC S7-200 SMART CPU SR20 (6ES7288-1SR20-0AA0) (All versions), SIMATIC S7-200 SMART CPU SR20 (6ES7288-1SR20-0AA1) (All versions), SIMATIC S7-200 SMART CPU SR30 (6ES7288-1SR30-0AA0) (All versions), SIMATIC S7-200 SMART CPU SR30 (6ES7288-1SR30-0AA1) (All versions), SIMATIC S7-200 SMART CPU SR40 (6ES7288-1SR40-0AA0) (All versions), SIMATIC S7-200 SMART CPU SR40 (6ES7288-1SR40-0AA1) (All versions), SIMATIC S7-200 SMART CPU SR60 (6ES7288-1SR60-0AA0) (All versions), SIMATIC S7-200 SMART CPU SR60 (6ES7288-1SR60-0AA1) (All versions), SIMATIC S7-200 SMART CPU ST20 (6ES7288-1ST20-0AA0) (All versions), SIMATIC S7-200 SMART CPU ST20 (6ES7288-1ST20-0AA1) (All versions), SIMATIC S7-200 SMART CPU ST30 (6ES7288-1ST30-0AA0) (All versions), SIMATIC S7-200 SMART CPU ST30 (6ES7288-1ST30-0AA1) (All versions), SIMATIC S7-200 SMART CPU ST40 (6ES7288-1ST40-0AA0) (All versions), SIMATIC S7-200 SMART CPU ST40 (6ES7288-1ST40-0AA1) (All versions), SIMATIC S7-200 SMART CPU ST60 (6ES7288-1ST60-0AA0) (All versions), SIMATIC S7-200 SMART CPU ST60 (6ES7288-1ST60-0AA1) (All versions). Affected devices do not properly handle TCP packets with an incorrect structure. This could allow an unauthenticated remote attacker to cause a denial of service condition. To restore normal operations, the network cable of the device needs to be unplugged and re-plugged.

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 confidence

The SIMATIC S7-200 SMART CPU devices fail to properly validate TCP packets with incorrect structure, causing the network stack to become unresponsive. An unauthenticated remote attacker sending specially crafted malformed TCP packets can trigger a denial of service, rendering the device unreachable until the network cable is physically disconnected and reconnected.

MitigationIsolate affected devices behind industrial firewalls or VLANs to limit exposure to untrusted networks. Monitor Siemens for firmware updates addressing this vulnerability.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

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 device model
    Locate the physical SIMATIC S7-200 SMART CPU and verify the model number on the device labeling, or check the device inventory/asset management system for S7-200 SMART controllers
    Affected if The device is a SIMATIC S7-200 SMART CPU
  2. Determine the firmware version
    Access the device via STEP 7 MicroWIN SMART software or check the Siemens product directory for the installed firmware version on the S7-200 SMART CPU
    Affected if The firmware version has not been updated to address this vulnerability (check Siemens advisory for current patched versions)
  3. Check network exposure
    Review network topology and firewall rules to determine if the S7-200 SMART CPU is directly accessible from untrusted or external networks without industrial firewall protection
    Affected if The device has direct accessibility from untrusted networks (e.g., internet, guest networks, or demilitarized zones)
  4. Verify network responsiveness
    Attempt to ping the device IP address and attempt a TCP connection to port 102 (S7 communication) from an engineering workstation on the same network segment
    Affected if The device is unreachable over the network despite the network cable being connected and physical link lights showing activity
  5. Check for exploit indicators
    If the device is unreachable, verify that network switches show active link lights on the port, and try accessing from a directly connected laptop to rule out simple network issues
    Affected if The device network stack is unresponsive (unreachable but physically connected with active link indicators)

A user is affected if they have a SIMATIC S7-200 SMART CPU that is either exposed to untrusted networks or already exhibiting network unresponsiveness that requires physical cable reconnection to restore.

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

Isolate affected devices behind industrial firewalls or VLANs to limit exposure to untrusted networks. Monitor Siemens for firmware updates addressing this vulnerability.

Have this fixed Scoped from the published advisory
  • Consultation8.0 h
  • Implementation10.0 h
  • Testing6.0 h
  • Review / QA4.0 h
28.0 hours of engineering $5,020
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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-2024-43647 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