CVE-2021-34780

Cisco Small Business 220 Series Smart Switches Link Layer Discovery Protocol Vulnerabilities

HIGH
8.8
CVSS Score
Published: October 6, 2021 at 07:45 PM UTC
Updated: June 17, 2026 at 03:56 AM UTC
33 products affected across 1 vendorBusiness 220-48t 4X FirmwareBusiness 220-16p 2G FirmwareBusiness 220-48t 4G Firmware

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Severity
HIGH8.8
Exploit prediction
EPSS 0.5%
SSVC
No known exploit

Description

Multiple 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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v ≤ 1.2.0.6
cisco-business-220-16p-2g (same device)
v ≤ 1.2.0.6
cisco-business-220-16t-2g (same device)
v ≤ 1.2.0.6
cisco-business-220-24fp-4g (same device)
v ≤ 1.2.0.6
cisco-business-220-24fp-4x (same device)
v ≤ 1.2.0.6
cisco-business-220-24p-4g (same device)
v ≤ 1.2.0.6
cisco-business-220-24p-4x (same device)
v ≤ 1.2.0.6
cisco-business-220-24t-4g (same device)
v ≤ 1.2.0.6
cisco-business-220-24t-4x (same device)
v ≤ 1.2.0.6
cisco-business-220-48fp-4x (same device)
v ≤ 1.2.0.6
cisco-business-220-48p-4g (same device)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
ADJACENT_NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-120

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