CVE-2016-7987
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 · uneditedAn issue was discovered in Siemens ETA4 firmware (all versions prior to Revision 08) of the SM-2558 extension module for: SICAM AK, SICAM TM 1703, SICAM BC 1703, and SICAM AK 3. Specially crafted packets sent to Port 2404/TCP could cause the affected device to go into defect mode. A cold start might be required to recover the system, a Denial-of-Service Vulnerability.
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 confidenceA remote unauthenticated attacker can send specially crafted packets to port 2404/TCP on affected Siemens SM-2558 extension modules running ETA4 firmware versions prior to Revision 08, causing the device to enter defect mode and require a cold restart to recover.
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<= 07<= 11.0CVSS 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:3.0/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 checksWork through these to decide whether this CVE applies to you.
-
Identify SM-2558 extension module presenceLocate the physical device or check network inventory for Siemens SM-2558 extension modules. This is a specific hardware module, so verify through asset inventory, network documentation, or physical inspection of industrial control equipment.Affected if The environment contains Siemens SM-2558 extension modules running the affected firmware.
-
Check ETA4 firmware revisionAccess the SM-2558 module through its management interface (typically web UI, console, or Siemens engineering software) and retrieve the firmware version information. Look for the ETA4 firmware revision number.Affected if The installed ETA4 firmware revision is earlier than Revision 08 (for example, Revision 07 or earlier).
-
Check ETA2 firmware versionAccess the SM-2558 module through its management interface and retrieve the ETA2 firmware version information.Affected if The installed ETA2 firmware version is 11.0 or earlier.
-
Verify port 2404/TCP accessibilityScan the network or check firewall rules to determine if port 2404/TCP on the SM-2558 module is exposed to untrusted network segments. Use a port scanner or review network access control lists.Affected if Port 2404/TCP is reachable from network segments accessible to unauthenticated users (such as the internet or untrusted corporate networks).
The environment is affected if SM-2558 modules with ETA4 firmware before Revision 08 or ETA2 firmware 11.0 or earlier have port 2404/TCP accessible to untrusted network actors.
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 dataUpgrade ETA4 firmware to Revision 08 or later; implement network segmentation to restrict access to port 2404/TCP until patches are applied.
- Consultation6.0 h
- Implementation4.0 h
- Testing6.0 h
- Review / QA3.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,376.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2016-7987 — 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-2016-7987 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
Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.
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.
- 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