CVE-2018-0177 : Vulnerability Insights and Analysis

A vulnerability in the IP Version 4 (IPv4) processing code of Cisco IOS XE Software running on Cisco Catalyst 3850 and Cisco Catalyst 3650 Series Switches could allow an unauthenticated, remote attacker to cause high CPU utilization, traceback messages, or a reload of an affected device that leads to a denial of service (DoS) condition. The vulnerability is due to incorrect processing of certain IPv4 packets. An attacker could exploit this vulnerability by sending specific IPv4 packets to an IPv4 address on an affected device. A successful exploit could allow the attacker to cause high CPU utilization, traceback messages, or a reload of the affected device that leads to a DoS condition. If the switch does not reboot when under attack, it would require manual intervention to reload the device. This vulnerability affects Cisco Catalyst 3850 and Cisco Catalyst 3650 Series Switches that are running Cisco IOS XE Software Release 16.1.1 or later, until the first fixed release, and are configured with an IPv4 address. Cisco Bug IDs: CSCvd80714.

Understanding CVE-2018-0177

This section provides insights into the nature and impact of CVE-2018-0177.

What is CVE-2018-0177?

CVE-2018-0177 is a vulnerability found in the code responsible for processing IPv4 in Cisco IOS XE Software, affecting Cisco Catalyst 3850 and Cisco Catalyst 3650 Series Switches. It allows an unauthenticated remote attacker to exploit the system.

The Impact of CVE-2018-0177

The consequences of this vulnerability include excessive CPU usage, traceback messages, and potential device restarts, leading to denial of service (DoS) situations. Attackers can disrupt operations by exploiting this flaw.

Technical Details of CVE-2018-0177

This section delves into the technical aspects of CVE-2018-0177.

Vulnerability Description

The vulnerability arises from erroneous handling of specific IPv4 packets in Cisco IOS XE Software, enabling attackers to disrupt devices remotely.

Affected Systems and Versions

Cisco Catalyst 3850 and Cisco Catalyst 3650 Series Switches
Cisco IOS XE Software Release 16.1.1 and subsequent versions until the fix

Exploitation Mechanism

Attackers send specific IPv4 packets to an IPv4 address on the affected device
Successful exploitation leads to high CPU usage, traceback messages, or device restarts

Mitigation and Prevention

Learn how to protect your systems from CVE-2018-0177.

Immediate Steps to Take

Apply patches and updates from Cisco promptly
Implement network segmentation to limit attack surfaces
Monitor network traffic for any suspicious activity

Long-Term Security Practices

Regularly update and patch network devices
Conduct security audits and assessments periodically
Educate staff on cybersecurity best practices

Patching and Updates

Install the latest fixed release from Cisco to address the vulnerability
Keep systems up to date with security patches and firmware updates