Vulnslist

find the latest Cisco vulnerabilities

Cisco Nexus 9000 Series Fabric Switches ACI Mode Fabric Infrastructure VLAN Unauthorized Access Vulnerability

cisco-sa-20190703-n9kaci-bypass · High · Published · Updated

A vulnerability in the fabric infrastructure VLAN connection establishment of the Cisco Nexus 9000 Series Application Centric Infrastructure (ACI) Mode Switch Software could allow an unauthenticated, adjacent attacker to bypass security validations and connect an unauthorized server to the infrastructure VLAN. The 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 malicious LLDP packet on the adjacent subnet to the Cisco Nexus 9000 Series Switch in ACI mode. 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 workarounds that address this vulnerability. This advisory is available at the following link: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190703-n9kaci-bypass

Cisco advisory ·CSAF JSON

Workarounds

If strict mode is configured, this vulnerability cannot be exploited. Strict mode enforces the following further firmware security checks before allowing a connection:

Allows only switches with a valid Cisco serial number and Secure Sockets Layer (SSL) certificate.
Requires serial number-based authorization.
Requires an administrator to manually authorize controllers and switches to join the fabric.

Administrators can determine if an interface is configured in strict mode by verifying that the system fabric-security-mode strict command is present in the running configuration.

apic# show running-config | grep strict system fabric-security-mode strict

For additional information on configuring strict mode, refer to Configuring Fabric Secure Mode https://www.cisco.com/c/en/us/td/docs/switches/datacenter/aci/apic/sw/1-x/cli/nx/cfg/b_APIC_NXOS_CLI_User_Guide/b_APIC_NXOS_CLI_User_Guide_chapter_01110.html#task_E123581BDA62418284F2206981AC322B .

CVEsCVE-2019-1890
Cisco Bug IDsCSCvp64280
CVSS ScoreBase 7.4
Base 7.4 CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N/E:X/RL:X/RC:X
Product Names From Source
Cisco NX-OS System Software in ACI Mode 12.2(2g), Cisco NX-OS System Software in ACI Mode 13.0(1i), Cisco NX-OS System Software in ACI Mode 13.0(2m), Cisco NX-OS System Software in ACI Mode 13.2(1l), Cisco NX-OS System Software in ACI Mode 13.2(1m), Cisco NX-OS System Software in ACI Mode 13.2(2l), Cisco NX-OS System Software in ACI Mode 13.2(2o), Cisco NX-OS System Software in ACI Mode 13.2(3i), Cisco NX-OS System Software in ACI Mode 13.2(3n), Cisco NX-OS System Software in ACI Mode 13.2(3o), Cisco NX-OS System Software in ACI Mode 13.2(3r), Cisco NX-OS System Software in ACI Mode 13.2(4d), Cisco NX-OS System Software in ACI Mode 13.2(4e), Cisco NX-OS System Software in ACI Mode 13.2(3j), Cisco NX-OS System Software in ACI Mode 13.2(3s), Cisco NX-OS System Software in ACI Mode 13.2(5d), Cisco NX-OS System Software in ACI Mode 13.2(5e), Cisco NX-OS System Software in ACI Mode 13.2(5f), Cisco NX-OS System Software in ACI Mode 13.2(6i), Cisco NX-OS System Software in ACI Mode 13.2(41d), Cisco NX-OS System Software in ACI Mode 13.2(7f), Cisco NX-OS System Software in ACI Mode 13.2(7k), Cisco NX-OS System Software in ACI Mode 14.0(1h), Cisco NX-OS System Software in ACI Mode 14.0(2c), Cisco NX-OS System Software in ACI Mode 14.0(3d), Cisco NX-OS System Software in ACI Mode 14.0(3c), Cisco NX-OS System Software in ACI Mode 14.1(1i), Cisco NX-OS System Software in ACI Mode 14.1(1j), Cisco NX-OS System Software in ACI Mode 14.1(1k), Cisco NX-OS System Software in ACI Mode 14.1(1l), Cisco NX-OS System Software in ACI Mode, Cisco Nexus 9000 Series Switches

CSAF Product Statuses

Product Status Source CVE Rows
12.2(2g) known_affected cisco_csaf CVE-2019-1890 1
13.0(1i) known_affected cisco_csaf CVE-2019-1890 1
13.0(2m) known_affected cisco_csaf CVE-2019-1890 1
Cisco NX-OS System Software in ACI Mode 13.2(1l) when installed on Cisco Nexus 9000 Series Switches known_affected cisco_csaf CVE-2019-1890 1
Cisco NX-OS System Software in ACI Mode 13.2(1m) when installed on Cisco Nexus 9000 Series Switches known_affected cisco_csaf CVE-2019-1890 1
Cisco NX-OS System Software in ACI Mode 13.2(2l) when installed on Cisco Nexus 9000 Series Switches known_affected cisco_csaf CVE-2019-1890 1
Cisco NX-OS System Software in ACI Mode 13.2(2o) when installed on Cisco Nexus 9000 Series Switches known_affected cisco_csaf CVE-2019-1890 1
Cisco NX-OS System Software in ACI Mode 13.2(3i) when installed on Cisco Nexus 9000 Series Switches known_affected cisco_csaf CVE-2019-1890 1
Cisco NX-OS System Software in ACI Mode 13.2(3j) when installed on Cisco Nexus 9000 Series Switches known_affected cisco_csaf CVE-2019-1890 1
Cisco NX-OS System Software in ACI Mode 13.2(3n) when installed on Cisco Nexus 9000 Series Switches known_affected cisco_csaf CVE-2019-1890 1
Cisco NX-OS System Software in ACI Mode 13.2(3o) when installed on Cisco Nexus 9000 Series Switches known_affected cisco_csaf CVE-2019-1890 1
Cisco NX-OS System Software in ACI Mode 13.2(3r) when installed on Cisco Nexus 9000 Series Switches known_affected cisco_csaf CVE-2019-1890 1

Showing 12 of 30 CSAF status groups; 18 more not shown.

Related Products

Product CVE Evidence
Cisco Application Policy Infrastructure Controller (APIC) CVE-2019-1890 Cisco OpenVuln
Cisco NX-OS Software CVE-2019-1890 Cisco OpenVuln
Cisco NX-OS System Software in ACI Mode CVE-2019-1890 Cisco OpenVuln
Cisco Nexus 9000 Series Switches CVE-2019-1890 Cisco OpenVuln · family-level