CVE-2019-1890 : What You Need to Know
Learn about CVE-2019-1890, a high-severity vulnerability in Cisco Nexus 9000 Series ACI Mode Switch Software allowing unauthorized server connections. Find mitigation steps here.
A vulnerability in the Cisco Nexus 9000 Series Application Centric Infrastructure (ACI) Mode Switch Software allows an adjacent attacker to connect an unauthorized server to the infrastructure VLAN, potentially compromising security.
Understanding CVE-2019-1890
This CVE involves a security vulnerability in the Cisco Nexus 9000 Series ACI Mode Switch Software that could lead to unauthorized access to the infrastructure VLAN.
What is CVE-2019-1890?
The vulnerability arises during the establishment of the fabric infrastructure VLAN connection, enabling an unauthenticated adjacent attacker to bypass security validations and connect an unauthorized server to the infrastructure VLAN.
The Impact of CVE-2019-1890
- Attack Vector: Adjacent Network
- Base Score: 7.4 (High Severity)
- Integrity Impact: High
- Scope: Changed
- Privileges Required: None
- Exploitation: An attacker can send a malicious LLDP packet to the Cisco Nexus 9000 Series Switch in ACI mode, gaining access to the infrastructure VLAN.
Technical Details of CVE-2019-1890
Vulnerability Description
The vulnerability allows unauthorized connection of a server to the highly privileged infrastructure VLAN due to inadequate security requirements during LLDP setup.
Affected Systems and Versions
- Affected Product: Cisco NX-OS System Software in ACI Mode 11.0.1b
- Affected Version: Less than 14.1(2g)
Exploitation Mechanism
- Attacker sends a malicious LLDP packet on the adjacent subnet to the Cisco Nexus 9000 Series Switch in ACI mode.
Mitigation and Prevention
Immediate Steps to Take
- Apply the necessary patches provided by Cisco to address the vulnerability.
- Monitor network traffic for any suspicious activities.
Long-Term Security Practices
- Implement network segmentation to limit unauthorized access.
- Regularly update and patch network devices to prevent security vulnerabilities.
Patching and Updates
- Cisco has released patches to mitigate the vulnerability. Ensure timely installation of these patches to secure the infrastructure.