CVE-2014-2254
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 · uneditedSiemens SIMATIC S7-1200 CPU PLC devices with firmware before 4.0 allow remote attackers to cause a denial of service (defect-mode transition) via crafted HTTP packets, a different vulnerability than CVE-2014-2255.
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 confidenceSiemens SIMATIC S7-1200 CPU PLC devices with firmware versions prior to 4.0 contain a denial-of-service vulnerability where remote attackers can send crafted HTTP packets to trigger a defect-mode transition, causing the PLC to enter a fault state and cease normal operations.
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<= 3.0.2= 3.0all versionsall versionsall versionsall versionsall versionsCVSS 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
- Authentication
- None
- Confidentiality
- None
- Integrity
- None
- Availability
- Complete
AV:N/AC:L/Au:N/C:N/I:N/A:C
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 the SIMATIC S7-1200 CPU modelAccess the PLC via TIA Portal, STEP 7, or the PLC's built-in web server to read the device nameplate or device identification. Look for model numbers such as 1211c, 1212c, 1214c, 1215c, 1217c, or generic S7-1200 CPU.Affected if The CPU model is any of the following: 1211c, 1212c, 1214c, 1215c, or 1217c (all versions of these models are affected).
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Check the firmware version of the S7-1200 CPURetrieve the firmware version through the TIA Portal device overview, the PLC's web interface under 'Device Information', or via STEP 7/STEP 7 MicroWin by accessing the CPU properties. Note the exact firmware version number.Affected if The firmware version is 3.0, 3.0.2, or any version lower than 3.0.2 (firmware <= 3.0.2). Note that models 1211c, 1212c, 1214c, 1215c, and 1217c are affected at ALL versions regardless of firmware.
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Determine if the HTTP web interface is enabledAccess the PLC configuration in TIA Portal or STEP 7 and check the 'Web Server' settings under the CPU properties. Alternatively, attempt to access the PLC's IP address via HTTP from a browser to see if a web page loads.Affected if The HTTP web server is enabled and accessible on the network, as this is the attack vector for the crafted HTTP packets.
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Verify the PLC operational statusCheck the PLC status via TIA Portal online diagnostics, STEP 7, or by observing the LED indicators on the physical PLC module (specifically the RUN/STOP and ERROR lights).Affected if The PLC is in DEFECT mode, FAULT state, or showing ERROR status indicators, which may indicate successful exploitation of this vulnerability.
Your environment is affected if you have a SIMATIC S7-1200 CPU model 1211c, 1212c, 1214c, 1215c, or 1217c at any version, or any S7-1200 CPU with firmware version 3.0.2 or lower, and the HTTP web interface is enabled and exposed on the network.
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 dataUpdate SIMATIC S7-1200 firmware to version 4.0 or later to remediate this vulnerability. Additionally, restrict network access to the PLC's HTTP interface using firewalls or network segmentation to limit exposure to unauthenticated HTTP-based attacks.
- Consultation4.0 h
- Implementation3.0 h
- Testing4.0 h
- Review / QA2.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2014-2254 — 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-2014-2254 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
- No weaponised exploit code, or anything meant to cause harm
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