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S7 1200 Cpu 1211c FirmwareOperating system · Siemens

CVE-2019-13940

HIGH · 7.5 CVSS v3.1 Published 2020-02-11
Fix available
A fix is available. Upgrade to 4.1 or later.
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 ET 200pro IM154-8 PN/DP CPU (All versions < V3.X.17), SIMATIC ET 200pro IM154-8F PN/DP CPU (All versions < V3.X.17), SIMATIC ET 200pro IM154-8FX PN/DP CPU (All versions < V3.X.17), SIMATIC ET 200S IM151-8 PN/DP CPU (All versions < V3.X.17), SIMATIC ET 200S IM151-8F PN/DP CPU (All versions < V3.X.17), SIMATIC S7-1200 CPU family (incl. SIPLUS variants) (All versions < V4.1), SIMATIC S7-300 CPU 314C-2 PN/DP (All versions < V3.X.17), SIMATIC S7-300 CPU 315-2 PN/DP (All versions < V3.X.17), SIMATIC S7-300 CPU 315F-2 PN/DP (All versions < V3.X.17), SIMATIC S7-300 CPU 315T-3 PN/DP (All versions < V3.X.17), SIMATIC S7-300 CPU 317-2 PN/DP (All versions < V3.X.17), SIMATIC S7-300 CPU 317F-2 PN/DP (All versions < V3.X.17), SIMATIC S7-300 CPU 317T-3 PN/DP (All versions < V3.X.17), SIMATIC S7-300 CPU 317TF-3 PN/DP (All versions < V3.X.17), SIMATIC S7-300 CPU 319-3 PN/DP (All versions < V3.X.17), SIMATIC S7-300 CPU 319F-3 PN/DP (All versions < V3.X.17), SIMATIC S7-400 PN/DP V6 and below CPU family (incl. SIPLUS variants) (All versions), SIMATIC S7-400 PN/DP V7 CPU family (incl. SIPLUS variants) (All versions), SIMATIC WinAC RTX 2010 (All versions), SIMATIC WinAC RTX F 2010 (All versions), SIPLUS ET 200S IM151-8 PN/DP CPU (All versions < V3.X.17), SIPLUS ET 200S IM151-8F PN/DP CPU (All versions < V3.X.17), SIPLUS S7-300 CPU 314C-2 PN/DP (All versions < V3.X.17), SIPLUS S7-300 CPU 315-2 PN/DP (All versions < V3.X.17), SIPLUS S7-300 CPU 315F-2 PN/DP (All versions < V3.X.17), SIPLUS S7-300 CPU 317-2 PN/DP (All versions < V3.X.17), SIPLUS S7-300 CPU 317F-2 PN/DP (All versions < V3.X.17). Affected devices contain a vulnerability that could cause a denial of service condition of the web server by sending specially crafted HTTP requests to ports 80/tcp and 443/tcp. Beyond the web service, no other functions or interfaces are affected by the denial of service condition.

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

Multiple Siemens SIMATIC industrial controllers contain a denial of service vulnerability in their built-in web servers (ports 80/tcp and 443/tcp). Attackers can cause the web server to become unavailable by sending specially crafted HTTP requests, though this does not affect other device functions or interfaces.

MitigationUpdate affected devices to the vendor-specified versions (V3.X.17 for most models, V4.1 for S7-1200 family). If immediate patching is not feasible, consider network segmentation to restrict access to HTTP/HTTPS ports.

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
S7 1200 Cpu 1211c FirmwareOperating system
Affected:< 4.1
S7 1200 Cpu 1212c FirmwareOperating system
Affected:< 4.1
S7 1200 Cpu 1214c FirmwareOperating system
Affected:< 4.1
S7 1200 Cpu 1215c FirmwareOperating system
Affected:< 4.1
S7 1200 Cpu 1217c FirmwareOperating system
Affected:< 4.1
S7 1200 Cpu 1212fc FirmwareOperating system
Affected:< 4.1
S7 1200 Cpu 1214fc FirmwareOperating system
Affected:< 4.1
S7 1200 Cpu 1215fc FirmwareOperating system
Affected:< 4.1

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
    Access the device via TIA Portal or check the physical device labeling to confirm it is a Siemens S7 1200 CPU model 1211c, 1212c, 1214c, 1215c, 1217c, 1212fc, 1214fc, or 1215fc
    Affected if The device is not one of these eight models, then it is not affected by this CVE
  2. Verify the web server is enabled
    Attempt to access the device web interface on ports 80/tcp (HTTP) or 443/tcp (HTTPS) using a web browser or network scan tool such as nmap -p 80,443 <device_ip>
    Affected if Ports 80 and 443 are open and responding, the web server is enabled and the device could be affected
  3. Check the firmware version
    Log into the device web interface (if accessible) or connect via TIA Portal and navigate to the device properties to view the current firmware version
    Affected if The firmware version is less than 4.1 (for example, V3.x versions), the device is vulnerable

A user is affected if they have an S7 1200 CPU (1211c, 1212c, 1214c, 1215c, 1217c, 1212fc, 1214fc, or 1215fc) with the built-in web server enabled and running firmware version lower than 4.1.

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
Upgrade available Upgrade to 4.1 or later
Fixed in 4.1
Interim mitigation

Update affected devices to the vendor-specified versions (V3.X.17 for most models, V4.1 for S7-1200 family). If immediate patching is not feasible, consider network segmentation to restrict access to HTTP/HTTPS ports.

Fix this in S7 1200 Cpu 1211c Firmware Scoped from the published advisory
  • Consultation6.0 h
  • Implementation16.0 h
  • Testing8.0 h
  • Review / QA4.0 h
34.0 hours of engineering $6,000
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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-2019-13940 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
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