Cisco Nexus 9000 ACI LLDP Unauthorized Access Vulnerability (CVE-2021-1228)

Critical Vulnerability Information Vulnerability Overview Title: Cisco Nexus 9000 Series Fabric Switches ACI Mode Fabric Infrastructure VLAN Unauthorized Access Vulnerability Severity: High CVE ID: CVE-2021-1228 CVSS Score: 7.4 Cisco Bug ID: CSCvu84576 Vulnerability Description Summary: A vulnerability exists in the fabric infrastructure VLAN connection establishment process of Cisco Nexus 9000 Series Fabric Switches operating in ACI mode, allowing an unauthenticated adjacent attacker to bypass security validation and connect unauthorized servers to the infrastructure VLAN. Root Cause: Due to insufficient security requirements during the Link Layer Discovery Protocol (LLDP) configuration phase. Affected Products Affected Products: Cisco Nexus 9000 Series Fabric Switches operating in ACI mode with default configuration. Unaffected Products: Includes various Cisco products such as Firepower 1000 Series, Nexus 3000 Series, UCS 6200 Series, etc. Workarounds No available workarounds. Fix Software Cisco has released free software updates to address this vulnerability. Customers must comply with Cisco’s software license agreement. Other Resources Provides multiple links for additional information on Cisco security advisories and patches. Vulnerability Report Source Thank you to Adrien Peter of Synacktiv for reporting this vulnerability. URL https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-n9kaci-unauth-access-5PWzDx2w Revision History Version 1.1: Updated summary text to reflect no available workarounds. Version 1.0: Initial public release.

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Cisco Nexus 9000 ACI LLDP Unauthorized Access Vulnerability (CVE-2021-1228)