CVE Vulnerabilities

CVE-2019-1890

Improper Access Control

Published: Jul 04, 2019 | Modified: Nov 21, 2024
CVSS 3.x
6.5
MEDIUM
Source:
NVD
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
CVSS 2.x
3.3 LOW
AV:A/AC:L/Au:N/C:N/I:P/A:N
RedHat/V2
RedHat/V3
Ubuntu

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.

Weakness

The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor.

Affected Software

Name Vendor Start Version End Version
Application_policy_infrastructure_controller Cisco 7.3(0)zn(0.113) (including) 7.3(0)zn(0.113) (including)

Extended Description

Access control involves the use of several protection mechanisms such as:

When any mechanism is not applied or otherwise fails, attackers can compromise the security of the product by gaining privileges, reading sensitive information, executing commands, evading detection, etc. There are two distinct behaviors that can introduce access control weaknesses:

Potential Mitigations

  • Compartmentalize the system to have “safe” areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area.
  • Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.

References