CVE-2019-1968 : Security Advisory and Response

Cisco NX-OS Software NX-API Denial of Service Vulnerability

Understanding CVE-2019-1968

A vulnerability in Cisco NX-OS Software allows an unauthenticated attacker to trigger an unintended restart of a system process through the NX-API feature.

What is CVE-2019-1968?

The vulnerability arises from inadequate validation of the HTTP header in a specific request to the NX-API, enabling a remote attacker to exploit this weakness by sending a crafted HTTP request to the affected device.

The Impact of CVE-2019-1968

Successful exploitation could lead to a denial of service (DoS) situation within the NX-API service while keeping the NX-OS device operational for network traffic.

Technical Details of CVE-2019-1968

Vulnerability Description

The vulnerability in Cisco NX-OS Software allows an unauthenticated attacker to restart a system process by exploiting the NX-API feature's HTTP header validation flaw.

Affected Systems and Versions

Product: Cisco NX-OS Software 6.0(2)A4(1)
Versions Affected: < 8.3(2)

Exploitation Mechanism

Attacker sends a precisely crafted HTTP request to the NX-API on the affected device to trigger the vulnerability.

Mitigation and Prevention

Immediate Steps to Take

Ensure the NX-API feature is disabled if not in use to mitigate the risk.
Regularly monitor Cisco's security advisories for updates and patches.

Long-Term Security Practices

Implement network segmentation to limit the impact of potential attacks.
Conduct regular security assessments and audits to identify vulnerabilities.

Patching and Updates

Apply patches and updates provided by Cisco to address the vulnerability.