CVE-2017-3804 : Exploit Details and Defense Strategies

A security vulnerability in Cisco Nexus 5000, 6000, and 7000 Series Switches software related to the IS-IS protocol packet processing could allow an adjacent attacker to cause a device reload.

Understanding CVE-2017-3804

This CVE involves a vulnerability in the IS-IS protocol packet processing of Cisco Nexus switches, potentially leading to device crashes.

What is CVE-2017-3804?

The vulnerability in Cisco Nexus switches' software allows an adjacent attacker to trigger a device reload without authentication by exploiting crafted link-state packets.

The Impact of CVE-2017-3804

An adjacent attacker can cause a reload of the affected device without needing authentication.
Switches in the FabricPath domain may crash due to a specific IS-IS packet processing issue.

Technical Details of CVE-2017-3804

This section provides detailed technical information about the CVE.

Vulnerability Description

The vulnerability is related to the IS-IS protocol packet processing in Cisco Nexus 5000, 6000, and 7000 Series Switches software.
Crafted link-state packets can trigger a device reload without authentication.

Affected Systems and Versions

Affected versions include 7.1(3)N1(2.1), 7.1(3)N1(3.12), 7.3(2)N1(0.296), and 8.0(1)S2.

Exploitation Mechanism

An adjacent attacker can exploit the vulnerability by sending specially crafted link-state packets to the affected device.

Mitigation and Prevention

Steps to address and prevent the CVE.

Immediate Steps to Take

Apply patches for the fixed releases mentioned to mitigate the vulnerability.
Monitor network traffic for any signs of exploitation.

Long-Term Security Practices

Regularly update and patch network devices to prevent known vulnerabilities.
Implement network segmentation and access controls to limit the attack surface.

Patching and Updates

Ensure all affected systems are updated with the fixed releases provided by Cisco.