Catalyst 12xx Supervisor SoftwareApplication · Cisco
CVE-1999-0430
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 · uneditedCisco Catalyst LAN switches running Catalyst 5000 supervisor software allows remote attackers to perform a denial of service by forcing the supervisor module to reload.
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 · low confidenceThis is a denial-of-service vulnerability in Cisco Catalyst 5000 series LAN switches running Catalyst 5000 supervisor software. The vulnerability allows remote attackers to force the supervisor module to reload, causing interruption of switching services.
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
Catalyst 12xx Supervisor SoftwareApplication
= 4.29
Catalyst 29xx Supervisor SoftwareApplication
= 1.0= 2.1.5= 2.1.501= 2.1.502
Catalyst 5xxx Supervisor SoftwareApplication
= 1.0= 2.1.5= 2.1.501= 2.1.502CVSS 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
- Partial
AV:N/AC:L/Au:N/C:N/I:N/A:P
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 Catalyst switch modelUse the 'show version' command or physically label the device to confirm it is a Catalyst 12xx, 29xx, or 5xxx series switchAffected if The device is a Cisco Catalyst 12xx, 29xx, or 5xxx series switch
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Check the supervisor software versionExecute 'show version' on the switch CLI and locate the version string labeled as 'Supervisor Software' or similarAffected if The displayed version matches exactly 4.29 (for 12xx), or 1.0, 2.1.5, 2.1.501, or 2.1.502 (for 29xx or 5xxx)
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Confirm the supervisor module is activeExecute 'show module' to verify the supervisor module is present and in 'ok' statusAffected if The supervisor module is running and responsive (the vulnerability requires an active supervisor module to be exploitable)
If the switch is a Catalyst 12xx, 29xx, or 5xxx series running any of the exact versions listed (4.29, 1.0, 2.1.5, 2.1.501, or 2.1.502), the device is affected by this denial-of-service vulnerability.
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 dataDue to the age of this vulnerability (1999) and affected hardware (Catalyst 5000 series), the primary mitigation is to upgrade to modern switching hardware and current software versions, as the affected products are long End-of-Life. Network segmentation and access controls can provide interim protection.
Fix this in Catalyst 12xx Supervisor Software
Scoped from the published advisory
- Consultation4.0 h
- Implementation8.0 h
- Testing4.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,120.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-1999-0430 — 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-1999-0430 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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