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CVE-2021-1228

HIGH severity · CVSS 7.4 · Improper access control
7.4CVSS HIGH

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.

Impact & exploitability

Attack vectorAdjacent
Attack complexityLow
Privileges requiredNone
User interactionNone
Confidentiality impactNone
Integrity impactHigh
Availability impactNone
Exploit probability (EPSS)0%

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N

Affected products we track (1)

Recommendation

Apply the vendor fix promptly. Open any affected product above for its exact safe version.