Business 220 8t E 2g FirmwareOperating system · Cisco
CVE-2021-34779
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 · uneditedMultiple vulnerabilities exist in the Link Layer Discovery Protocol (LLDP) implementation for Cisco Small Business 220 Series Smart Switches. An unauthenticated, adjacent attacker could perform the following: Execute code on the affected device or cause it to reload unexpectedly Cause LLDP database corruption on the affected device For more information about these vulnerabilities, see the Details section of this advisory. Note: LLDP is a Layer 2 protocol. To exploit these vulnerabilities, an attacker must be in the same broadcast domain as the affected device (Layer 2 adjacent). Cisco has released firmware updates that address these vulnerabilities.
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 confidenceMultiple vulnerabilities exist in the LLDP implementation on Cisco Small Business 220 Series Smart Switches. An unauthenticated, Layer 2 adjacent attacker can send specially crafted LLDP packets to execute arbitrary code, cause unexpected device reloads, or corrupt the LLDP database. The attacker must be on the same broadcast domain as the affected device.
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
Business 220 8t E 2g FirmwareOperating system
<= 1.2.0.6
Business 220 8p E 2g FirmwareOperating system
<= 1.2.0.6
Business 220 8fp E 2g FirmwareOperating system
<= 1.2.0.6
Business 220 16t 2g FirmwareOperating system
<= 1.2.0.6
Business 220 16p 2g FirmwareOperating system
<= 1.2.0.6
Business 220 24t 4g FirmwareOperating system
<= 1.2.0.6
Business 220 24p 4g FirmwareOperating system
<= 1.2.0.6
Business 220 24fp 4g FirmwareOperating system
<= 1.2.0.6CVSS 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
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/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 modelCheck the switch model through the web interface, CLI command 'show version', or physical label. Confirm it is a Cisco Business 220 series model (8t, 8p, 8fp, 16t, 16p, 24t, 24p, or 24fp).Affected if Device is a Cisco Business 220 series switch
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Check firmware versionAccess the switch web interface under Device Info or use the CLI command 'show version' to determine the installed firmware version.Affected if Firmware version is 1.2.0.6 or lower
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Verify LLDP is enabledCheck LLDP status via the web interface (LLDP > LLDP Settings) or CLI command 'show lldp' to see if LLDP is enabled on any ports.Affected if LLDP is enabled on the switch
You are affected if you have a Cisco Business 220 series switch running firmware version 1.2.0.6 or lower with LLDP enabled, as the vulnerability requires LLDP to be active for exploitation by a Layer 2 adjacent attacker.
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 dataApply the Cisco firmware updates for the Small Business 220 Series Smart Switches. As a compensating control, disable LLDP on unused ports or implement network segmentation to restrict Layer 2 adjacency.
Fix this in Business 220 8t E 2g Firmware
Scoped from the published advisory
- Consultation3.0 h
- Implementation6.0 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 $4,224.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-34779 — 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-2021-34779 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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