Home/CVE/A vulnerability in the Link Layer Discovery Protocol (LLDP) for Nexus 9000 Series Fabric Switches in Application Centric
CVE

CVE-2021-1231

A vulnerability in the Link Layer Discovery Protocol (LLDP) for Nexus 9000 Series Fabric Switches in Application Centric

A vulnerability in the Link Layer Discovery Protocol (LLDP) for Nexus 9000 Series Fabric Switches in Application Centric Infrastructure (ACI) mode could allow an unauthenticated, adjacent attacker to disable switching on a small form-factor pluggable (SFP) interface. This vulnerability is due to incomplete validation of the source of a received LLDP packet. An attacker could exploit this vulnerability by sending a crafted LLDP packet on an SFP interface to an affected device.

A successful exploit could allow the attacker to disable switching on the SFP interface, which could disrupt network traffic.

MEDIUM · CVSS 4.7 EPSS 0.00117
Monitor
  • No active-exploitation, high-EPSS, or public-exploit signals - routine patching cadence
Sigma rules0 YARA rules0
⬡

Weakness Classification

CWE-284Improper Access Control
CWE-346Origin Validation Error
▤

Affected Products & Versions

1
cisco nx-osall versions
▣

Scoring & Timeline

4.7
MEDIUM · CVSS v3.1 · psirt@cisco.com
View on NVD
Attack Vector
Network Adjacent Local Physical
Attack Complexity
Low High
Privileges Required
None Low High
User Interaction
None Required
Scope
Unchanged Changed
Confidentiality
None Low High
Integrity
None Low High
Availability
None Low High
Published to NVD24 Feb 2021 · 08:15 PM
CVSS VectorCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L
SSVC triage · cisa-vulnrichment
Exploitation
none
Automatable
no
Technical impact
partial
SSVC asks the questions that actually drive patch urgency: is it being exploited, can attacks be automated, and how total is the impact.
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Vendor Advisories

1
cisco-csafcisco-sa-apic-lldap-dos-WerV9CFj
🔗

References & Sources

1
Source URLs (vendor pages, mailing lists, write-ups). Exploit/PoC links are in their own section above to avoid duplication.
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-apic-lldap-dos-WerV9CFjVendor Advisory
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