CVE-2017-20233
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 · uneditedHirschmann HiLCOS products OpenBAT, BAT450, WLC, BAT867 contains a firewall filtering vulnerability that fails to correctly filter IPv4 multicast and broadcast traffic when management IP address filtering is disabled, allowing configured filter rules to be bypassed. Attackers with network access can inject or observe multicast and broadcast packets that should have been blocked by the firewall.
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 confidenceHirschmann HiLCOS products (OpenBAT, BAT450, WLC, BAT867) contain a firewall bypass vulnerability where IPv4 multicast and broadcast traffic fails to be correctly filtered when management IP address filtering is disabled. This allows configured filter rules to be circumvented, permitting attackers with network access to inject or observe multicast and broadcast packets that should be blocked.
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
- Adjacent
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
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 device and HiLCOS versionAccess the Hirschmann device web interface or CLI and locate the firmware/OS version information. This is typically found under System > Hardware/Software Info or via 'show version' command.Affected if Device is running Hirschmann HiLCOS firmware and version cannot be confirmed as patched (vendor did not publish specific version ranges)
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Locate management IP address filtering settingNavigate to the firewall or security configuration section in the HiLCOS web interface or CLI. Look for settings named 'Management IP Filtering', 'IP Filter', or 'Management Access Control'. This is typically under Firewall > Rules or Security > Access Control.Affected if The management IP address filtering setting is found and is currently DISABLED or set to 'off'
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Verify firewall rule configuration for multicast/broadcastExamine the firewall rule set to determine if any rules are configured to filter, block, or allow IPv4 multicast (224.0.0.0/4) or broadcast traffic. Check firewall policy tables or rule lists for destination addresses in the multicast range or broadcast addresses.Affected if Firewall rules exist that are intended to block or filter multicast/broadcast traffic but management IP filtering is disabled
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Confirm network exposureDetermine if the Hirschmann device is directly accessible on the network segment where multicast/broadcast traffic originates. Assess whether untrusted network segments can send multicast or broadcast packets to the device.Affected if Device is accessible from network segments where untrusted multicast/broadcast traffic could be received
The environment is affected if the Hirschmann HiLCOS device has management IP address filtering disabled while firewall rules exist that are intended to filter IPv4 multicast or broadcast traffic.
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 dataEnable management IP address filtering to prevent the firewall bypass; if unavailable, apply network segmentation to restrict unauthorized access to multicast/broadcast traffic.
- Consultation4.0 h
- Implementation6.0 h
- Testing4.0 h
- Review / QA2.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2017-20233 — 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-2017-20233 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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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
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