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CVE-2021-1228

MEDIUMCVSS 6.5/10EPSS 0.38%

Last modified

CVE-2021-1228 is a medium-severity vulnerability rated 6.5/10 on the CVSS scale. 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. EPSS estimates a 0.38% chance of exploitation in the next 30 days.

Description

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.

Metrics

CVSS 3.1
6.5/10

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

EPSS Probability
0.38%

29.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
CiscoNx-Os11.0\(1b\)
CiscoNx-Os11.0\(1c\)
CiscoNx-Os11.0\(1d\)
CiscoNx-Os11.0\(1e\)
CiscoNx-Os11.0\(2j\)
CiscoNx-Os11.0\(2m\)
CiscoNx-Os11.0\(3f\)
CiscoNx-Os11.0\(3i\)
CiscoNx-Os11.0\(3k\)
CiscoNx-Os11.0\(3n\)
CiscoNx-Os11.0\(3o\)
CiscoNx-Os11.0\(4g\)
CiscoNx-Os11.0\(4h\)
CiscoNx-Os11.0\(4o\)
CiscoNx-Os11.0\(4q\)
CiscoNx-Os11.1\(1j\)
CiscoNx-Os11.1\(1o\)
CiscoNx-Os11.1\(1r\)
CiscoNx-Os11.1\(1s\)
CiscoNx-Os11.1\(2h\)
CiscoNx-Os11.1\(2i\)
CiscoNx-Os11.1\(3f\)
CiscoNx-Os11.1\(4e\)
CiscoNx-Os11.1\(4f\)
CiscoNx-Os11.1\(4g\)
CiscoNx-Os11.1\(4i\)
CiscoNx-Os11.1\(4l\)
CiscoNx-Os11.1\(4m\)
CiscoNx-Os11.2\(1i\)
CiscoNx-Os11.2\(1k\)
CiscoNx-Os11.2\(1m\)
CiscoNx-Os11.2\(2g\)
CiscoNx-Os11.2\(2h\)
CiscoNx-Os11.2\(2i\)
CiscoNx-Os11.2\(2j\)
CiscoNx-Os11.2\(3c\)
CiscoNx-Os11.2\(3e\)
CiscoNx-Os11.2\(3h\)
CiscoNx-Os11.2\(3m\)
CiscoNx-Os11.3\(1g\)
CiscoNx-Os11.3\(1h\)
CiscoNx-Os11.3\(1i\)
CiscoNx-Os11.3\(1j\)
CiscoNx-Os11.3\(2f\)
CiscoNx-Os11.3\(2h\)
CiscoNx-Os11.3\(2i\)
CiscoNx-Os11.3\(2j\)
CiscoNx-Os11.3\(2k\)
CiscoNx-Os12.0\(1m\)
CiscoNx-Os12.0\(1n\)

Showing 50 of 162 affected configurations. See NVD for the full list.

References

Timeline

Published
Last Modified
Status
Modified

Frequently Asked Questions

What is CVE-2021-1228?
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.
How severe is CVE-2021-1228?
CVE-2021-1228 has a CVSS score of 6.5/10 (MEDIUM severity). The EPSS model estimates a 0.38% probability of exploitation in the next 30 days.
How do I fix CVE-2021-1228?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-1228?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST