CVE-2020-9307
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 OS2, RSP, and RSPE devices before HiOS 08.3.00 allow a denial of service. An unauthenticated, adjacent attacker can cause an infinite loop on one of the HSR ring ports of the device. This effectively breaks the redundancy of the HSR ring. If the attacker can perform the same attack on a second device, the ring is broken into two parts (thus disrupting communication between devices in the different parts).
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 confidenceHirschmann OS2, RSP, and RSPE devices before HiOS 08.3.00 contain a vulnerability in the HSR (High-availability Seamless Redundancy) protocol implementation. An unauthenticated, adjacent attacker can send specially crafted packets to an HSR ring port, triggering an infinite loop that causes the device to stop forwarding traffic on that port. This breaks HSR ring redundancy, and if the attacker targets a second device in the ring, communication between the two resulting network partitions is disrupted.
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>= 07.0.04, < 07.1.00>= 08.0.00, < 08.3.00CVSS 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
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:A/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.
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Identify device model and firmware versionAccess the device CLI or web interface and retrieve the system information. Common commands include 'show version', 'show system', or viewing the device status page in the web UI.Affected if The device is a Hirschmann OS2, RSP, or RSPE model running HiOS firmware version 07.0.04 or higher but lower than 08.3.00.
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Verify if HSR protocol is enabledCheck the HSR configuration on the device. In the CLI, this is typically done with commands such as 'show hsr', 'show hsrm', or 'show redundancy' depending on the firmware syntax.Affected if HSR (High-availability Seamless Redundancy) protocol is enabled and configured on the device.
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Identify configured HSR ring portsReview the HSR ring port assignments. Look for ports explicitly configured as HSR ring ports in the device's HSR or redundancy settings.Affected if The device has one or more ports configured as HSR ring ports, as these are the targets for the specially crafted packets.
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Confirm device is part of an HSR ringCheck the HSR node status and ring topology. Verify if the device is actively participating in an HSR ring by reviewing the HSR neighbor table or ring status.Affected if The device is actively participating in an HSR ring, making it reachable to adjacent attackers on the HSR network.
A device is affected if it is a Hirschmann OS2, RSP, or RSPE running HiOS version 07.0.04 to 08.2.xx and has HSR protocol enabled with configured ring ports.
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 data07.1.0008.3.00
Apply the vendor firmware update to HiOS 08.3.00 or later. For systems where immediate patching is not feasible, implement network segmentation to restrict adjacent attacker access to the HSR ring ports, and monitor for anomalous traffic patterns indicating DoS conditions.
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 h
- Review / QA2.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2020-9307 — 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-2020-9307 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
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