CVE-2019-1595 : What You Need to Know

Cisco Nexus 5600 and 6000 Series Switches Fibre Channel over Ethernet Denial of Service Vulnerability

Understanding CVE-2019-1595

This CVE involves a vulnerability in Cisco NX-OS Software that could allow an unauthenticated attacker to trigger a denial of service (DoS) situation on affected devices.

What is CVE-2019-1595?

The vulnerability arises from an incorrect allocation of an internal interface index in the Fibre Channel over Ethernet (FCoE) protocol implementation in Cisco NX-OS Software. An attacker can exploit this flaw by sending a specially crafted FCoE packet across affected interfaces, leading to a DoS scenario.

The Impact of CVE-2019-1595

CVSS Base Score: 7.4 (High Severity)
Attack Vector: Adjacent Network
Availability Impact: High
The attacker can create a packet loop, significantly increasing data throughput on affected interfaces, resulting in a DoS situation.

Technical Details of CVE-2019-1595

This section provides detailed technical information about the vulnerability.

Vulnerability Description

The vulnerability in Cisco NX-OS Software allows an unauthenticated attacker to exploit the FCoE protocol implementation, causing a DoS condition due to incorrect internal interface index allocation.

Affected Systems and Versions

Affected Product: Cisco NX-OS Software
Affected Version: 7.3(5)N1(1)

Exploitation Mechanism

Attacker sends a specially crafted FCoE packet across affected interfaces
Triggers the vulnerability by incorrect internal interface index allocation
Creates a packet loop and increases data throughput, leading to a DoS scenario

Mitigation and Prevention

Protecting systems from CVE-2019-1595 requires immediate actions and long-term security practices.

Immediate Steps to Take

Apply the software update to version 7.3(5)N1(1) to mitigate the vulnerability
Monitor network traffic for any signs of exploitation

Long-Term Security Practices

Implement network segmentation to limit the impact of potential attacks
Regularly update and patch software to address security vulnerabilities

Patching and Updates

Ensure all affected devices are updated to version 7.3(5)N1(1) to eliminate the vulnerability