{"schema_version":"public-product-v1.1","generated_at":"2026-07-21T11:05:32Z","exposure_verdict":"not_assessed","verdict_reason":"Public evidence does not evaluate exact release, platform, enabled features, configuration, compensating controls, or live exposure.","advisory":{"id":"cisco-sa-n9kaci-unauth-access-5PWzDx2w","slug":"cisco-sa-n9kaci-unauth-access-5pwzdx2w","vendor":"Cisco","title":"Cisco Nexus 9000 Series Fabric Switches ACI Mode Fabric Infrastructure VLAN Unauthorized Access Vulnerability","summary":"A vulnerability in the fabric infrastructure VLAN connection establishment of Cisco Nexus 9000 Series Fabric Switches in Application Centric Infrastructure (ACI) Mode could allow an unauthenticated, adjacent attacker to bypass security validations and connect an unauthorized server to the infrastructure VLAN. This vulnerability is due to insufficient security requirements during the Link Layer Discovery Protocol (LLDP) setup phase of the infrastructure VLAN. An attacker could exploit this vulnerability by sending a crafted LLDP packet on the adjacent subnet to an affected device. A successful exploit could allow the attacker to connect an unauthorized server to the infrastructure VLAN, which is highly privileged. With a connection to the infrastructure VLAN, the attacker can make unauthorized connections to Cisco Application Policy Infrastructure Controller (APIC) services or join other host endpoints. Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability. This advisory is available at the following link:https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-n9kaci-unauth-access-5PWzDx2w This advisory is part of the February 2021 Cisco FXOS and NX-OS Software Security Advisory Bundled Publication. For a complete list of the advisories and links to them, see Cisco Event Response: February 2021 Cisco FXOS and NX-OS Software Security Advisory Bundled Publication.","severity":"High","published_at":"2021-02-24T16:00:00Z","updated_at":"2021-02-25T14:44:59Z","source_url":"https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-n9kaci-unauth-access-5PWzDx2w","csaf_url":"https://sec.cloudapps.cisco.com/security/center/contentjson/CiscoSecurityAdvisory/cisco-sa-n9kaci-unauth-access-5PWzDx2w/csaf/cisco-sa-n9kaci-unauth-access-5PWzDx2w.json","exposure_verdict":"not_assessed","verdict_reason":"Public evidence does not evaluate exact release, platform, enabled features, configuration, compensating controls, or live exposure."},"freshness":{"last_source_refreshed_at":"2026-07-21T05:16:34Z","latest_source_refresh_at":"2026-07-21T05:16:34Z","oldest_source_refresh_at":"2026-07-21T03:00:03Z","all_sources_fresh":true,"sources":[{"source":"cisco_advisories","label":"Cisco advisories","last_success_at":"2026-07-21T03:00:03Z","stale":false},{"source":"cisco_csaf","label":"Cisco CSAF","last_success_at":"2026-07-21T05:14:24Z","stale":false},{"source":"nvd_cves","label":"NVD CVEs","last_success_at":"2026-07-21T05:16:30Z","stale":false},{"source":"cisa_kev","label":"CISA KEV","last_success_at":"2026-07-21T05:16:31Z","stale":false},{"source":"first_epss","label":"EPSS","last_success_at":"2026-07-21T05:16:34Z","stale":false}]},"summary":{"cve_count":1,"visible_product_count":1,"public_evidence_count":1,"kev_count":0,"highest_epss":0.00373},"cves":[{"id":"CVE-2021-1228","kev":false,"epss":{"score":0.00373,"percentile":0.29646,"score_date":"2026-07-20","updated_at":"2026-07-21T05:16:34Z"}}],"public_evidence":[{"product":{"name":"Cisco Nexus 9000 Series Switches","slug":"cisco-nexus-9000-series-switches","vendor":"Cisco"},"cve":{"id":"CVE-2021-1228"},"evidence_type":"structured_affected","evidence_label":{"scope":"CSAF product evidence","label":"product_status known affected"},"evidence_source":"Cisco CSAF","source":"Cisco CSAF","source_document_fetched_at":"2026-07-20T04:21:51Z","csaf_status":"known_affected","csaf_product_status":"known_affected","csaf_product_status_path":"vulnerabilities[].product_status.known_affected","raw_product_name":"Cisco NX-OS System Software in ACI Mode 13.2(1l) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 13.2(1m) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 13.2(2l) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 13.2(2o) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 13.2(3i) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 13.2(3j) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 13.2(3n) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 13.2(3o) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 13.2(3r) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 13.2(3s) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 13.2(41d) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 13.2(4d) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 13.2(4e) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 13.2(5d) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 13.2(5e) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 13.2(5f) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 13.2(6i) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 13.2(7f) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 13.2(7k) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 13.2(8d) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 13.2(9b) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 13.2(9f) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 13.2(9h) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 14.0(1h) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 14.0(2c) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 14.0(3c) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 14.0(3d) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 14.1(1i) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 14.1(1j) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 14.1(1k) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 14.1(1l) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 14.1(2g) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 14.1(2m) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 14.1(2o) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 14.1(2s) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 14.1(2u) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 14.1(2w) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 14.1(2x) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 14.2(1i) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 14.2(1j) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 14.2(1l) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 14.2(2e) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 14.2(2f) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 14.2(2g) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 14.2(3j) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 14.2(3l) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 14.2(3n) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 14.2(3q) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 14.2(4i) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 14.2(4k) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 14.2(4o) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 14.2(4p) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 14.2(5k) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 15.0(1k) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 15.0(1l) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 15.0(2e) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 15.0(2h) when installed on Cisco Nexus 9000 Series Switches","exposure_verdict":"not_assessed","verdict_reason":"Public evidence does not evaluate exact release, platform, enabled features, configuration, compensating controls, or live exposure.","exposure_verdict_reason":"Public evidence does not evaluate exact release, platform, enabled features, configuration, compensating controls, or live exposure.","kev":false,"epss":{"score":0.00373,"score_date":"2026-07-20","updated_at":"2026-07-21T05:16:34Z"},"published_at":"2021-02-24T16:00:00Z","updated_at":"2021-02-25T14:44:59Z","advisory_updated_at":"2021-02-25T14:44:59Z","source_url":"https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-n9kaci-unauth-access-5PWzDx2w","remediation":{"url":"https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-n9kaci-unauth-access-5PWzDx2w"},"row_display_order":1}]}