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Small Business 500 Series Stackable Managed Switches FirmwareOperating system · Cisco

CVE-2018-0209

HIGH · 7.7 CVSS v3.1 Published 2018-03-08
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
83/100
Remediation priority · High
Remotely reachable Zero-click

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 in the Simple Network Management Protocol (SNMP) subsystem communication channel through the Cisco 550X Series Stackable Managed Switches could allow an authenticated, remote attacker to cause the device to reload unexpectedly, causing a denial of service (DoS) condition. The device nay need to be manually reloaded to recover. The vulnerability is due to lack of proper input throttling of ingress SNMP traffic over an internal interface. An attacker could exploit this vulnerability by sending a crafted, heavy stream of SNMP traffic to the targeted device. An exploit could allow the attacker to cause the device to reload unexpectedly, causing a DoS condition. Cisco Bug IDs: CSCvg22135.

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

Vulnerability in the SNMP subsystem of Cisco 550X Series Stackable Managed Switches allows an authenticated, remote attacker to cause unexpected device reloads (DoS) by sending a crafted heavy stream of SNMP traffic over an internal interface. The root cause is lack of proper input throttling on ingress SNMP traffic.

MitigationApply the Cisco firmware update addressing CSCvg22135. As interim measures, restrict SNMP access via ACLs, implement rate-limiting on SNMP traffic, and limit SNMP to read-only communities where possible.

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
Small Business 500 Series Stackable Managed Switches FirmwareOperating system
Affected:= 2.2.5.68= 2.3.0.130

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
Low
User interaction
None
Scope
Changed
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/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 checks

Work through these to decide whether this CVE applies to you.

  1. Identify the switch model
    Locate the device label or access the management console to confirm the model is a Cisco Small Business 500 Series or 550X Series Stackable Managed Switch.
    Affected if Model is NOT a Cisco Small Business 500 Series or 550X Series switch - then not affected.
  2. Check installed firmware version
    Access the switch CLI or web GUI and navigate to the status or system information page to view the current firmware version. In CLI, this is typically shown via 'show version' or displayed in the initial boot screen.
    Affected if Firmware version equals exactly 2.2.5.68 or 2.3.0.130 - then affected.
  3. Verify if SNMP is enabled
    In the switch web GUI, go to SNMP > SNMP Configuration or in CLI run 'show snmp' to check if SNMP is currently enabled on any interface.
    Affected if SNMP is enabled on any interface - then the vulnerability is present in the attack surface.
  4. Check SNMP access configuration
    In the web GUI under SNMP > SNMP Community, review which SNMP communities are configured and whether read-write access is granted. Also check under SNMP > SNMP Access List if an access control list is applied.
    Affected if SNMP has read-write communities configured or no ACL is applied to restrict SNMP access - then the device is more exposed.

The device is affected only if it is a Cisco Small Business 500 Series or 550X Series switch running firmware version 2.2.5.68 or 2.3.0.130, and SNMP is enabled on the device.

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

Apply the Cisco firmware update addressing CSCvg22135. As interim measures, restrict SNMP access via ACLs, implement rate-limiting on SNMP traffic, and limit SNMP to read-only communities where possible.

Fix this in Small Business 500 Series Stackable Managed Switches Firmware Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing2.0 h
  • Review / QA1.0 h
9.0 hours of engineering $1,600
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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-2018-0209 in production — separate from our analysis above.

No notes yet

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What this is

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.

What belongs here
  • 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
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