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Simatic S7 300 Cpu FirmwareOperating system · Siemens

CVE-2016-8673

HIGH · 8.8 CVSS v3.0 Published 2016-11-23
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
95/100
Remediation priority · Urgent
Remotely reachable No privileges

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 CP 343-1 Advanced (incl. SIPLUS NET variant) (All versions < V3.0.53), SIMATIC CP 443-1 Advanced (incl. SIPLUS NET variant) (All versions < V3.2.17), SIMATIC S7-300 PN/DP CPU family (incl. SIPLUS variants) (All versions), SIMATIC S7-400 PN/DP CPU family (incl. SIPLUS variants) (All versions). The integrated web server at port 80/TCP or port 443/TCP of the affected devices could allow remote attackers to perform actions with the permissions of an authenticated user, provided the targeted user has an active session and is induced to trigger the malicious request.

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

The integrated web servers in SIMATIC CP 343-1 Advanced, CP 443-1 Advanced, and S7-300/400 PN/DP CPU families are vulnerable to Cross-Site Request Forgery (CSRF). Attackers can perform actions with the permissions of an authenticated user by tricking them into triggering malicious requests, provided the user has an active session.

MitigationUpdate CP 343-1 Advanced to V3.0.53+ and CP 443-1 Advanced to V3.2.17+; for S7-300/400 families lacking patches, restrict web server access via network segmentation/firewall and implement CSRF protections.

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
Simatic S7 300 Cpu FirmwareOperating system
Affected:all versions
Simatic Cp 443 1 FirmwareOperating system
Affected:all versions
Simatic Cp 343 1 FirmwareOperating system
Affected:all versions
Simatic S7 400 Cpu FirmwareOperating system
Affected:all versions

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
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/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. Verify the device model and firmware version
    Access the device via SIMATIC Manager or TIA Portal and retrieve the firmware version from the device properties. For CP 343-1 Advanced, check the firmware version in the device configuration under 'Properties > General > Version'. For CP 443-1 Advanced and S7-300/400 CPUs, use the device info dialog or online diagnostics to query the firmware version.
    Affected if The device is a CP 343-1 Advanced, CP 443-1 Advanced, S7-300 CPU, or S7-400 CPU with any firmware version - all versions are affected per the CVE.
  2. Confirm the integrated web server is enabled
    In TIA Portal or SIMATIC Manager, open the device configuration and navigate to 'Web server' settings under the device properties. Check if the web server functionality is activated. For S7-300/400 CPUs, verify under 'Properties > Web server > General'.
    Affected if The web server is enabled - this is required for the CSRF vulnerability to be exploitable.
  3. Determine web server network accessibility
    Attempt to access the device's web interface by entering the device IP address in a web browser over HTTP/HTTPS ports (typically 80/443 or 8080/443). Check if a login prompt or web server page is returned.
    Affected if The web server is reachable over the network - this indicates the attack surface is exposed.
  4. Verify if users have active web server sessions
    Review the device or network logs for recent web server access and authenticated sessions. Check if user accounts with web server access privileges have logged in recently.
    Affected if Users have active or recent authenticated sessions to the web server - the CSRF attack requires a user with an active session to be tricked.

A user is affected if they operate any of the listed device models (CP 343-1 Advanced, CP 443-1 Advanced, S7-300, S7-400) with the integrated web server enabled and users have authenticated web server sessions.

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

Update CP 343-1 Advanced to V3.0.53+ and CP 443-1 Advanced to V3.2.17+; for S7-300/400 families lacking patches, restrict web server access via network segmentation/firewall and implement CSRF protections.

Fix this in Simatic S7 300 Cpu Firmware Scoped from the published advisory
  • Consultation6.0 h
  • Implementation12.0 h
  • Testing6.0 h
  • Review / QA3.0 h
27.0 hours of engineering $4,800
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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-2016-8673 in production — separate from our analysis above.

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What this is

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What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
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