CVE-2018-0291 Explained : Impact and Mitigation

A vulnerability in the Simple Network Management Protocol (SNMP) input packet processor of Cisco NX-OS Software could allow an authenticated, remote attacker to cause the SNMP application on an affected device to restart unexpectedly. The vulnerability is due to improper validation of SNMP protocol data units (PDUs) in SNMP packets. An attacker could exploit this vulnerability by sending a crafted SNMP packet to an affected device. A successful exploit could allow the attacker to cause the SNMP application to restart multiple times, leading to a system-level restart and a denial of service (DoS) condition. This vulnerability affects various Cisco products, including Nexus switches and UCS fabric interconnects.

Understanding CVE-2018-0291

This section provides insights into the nature and impact of CVE-2018-0291.

What is CVE-2018-0291?

CVE-2018-0291 is a vulnerability in the SNMP input packet processor of Cisco NX-OS Software, allowing an attacker to disrupt the SNMP application on affected devices, potentially leading to a denial of service situation.

The Impact of CVE-2018-0291

The vulnerability could result in an unexpected restart of the SNMP application on the affected device, potentially causing multiple restarts and ultimately leading to a system-level restart and a denial of service (DoS) situation.

Technical Details of CVE-2018-0291

This section delves into the technical aspects of CVE-2018-0291.

Vulnerability Description

The vulnerability stems from inadequate validation of SNMP protocol data units (PDUs) in SNMP packets, allowing an attacker to manipulate SNMP packets and disrupt the SNMP application on affected devices.

Affected Systems and Versions

Nexus 2000 Series Switches
Nexus 3000 Series Switches
Nexus 3500 Platform Switches
Nexus 3600 Platform Switches
Nexus 5500 Platform Switches
Nexus 5600 Platform Switches
Nexus 6000 Series Switches
Nexus 7000 Series Switches
Nexus 7700 Series Switches
Nexus 9000 Series Switches in standalone NX-OS mode
Nexus 9500 R-Series Line Cards and Fabric Modules
UCS 6100 Series Fabric Interconnects
UCS 6200 Series Fabric Interconnects
UCS 6300 Series Fabric Interconnects

Exploitation Mechanism

An authenticated remote attacker could exploit the vulnerability by sending a manipulated SNMP packet to the affected device, causing the SNMP application to restart unexpectedly and potentially leading to a denial of service (DoS) condition.

Mitigation and Prevention

This section outlines steps to mitigate and prevent the exploitation of CVE-2018-0291.

Immediate Steps to Take

Apply the latest security patches provided by Cisco to address the vulnerability.
Monitor network traffic for any suspicious SNMP activities.
Restrict SNMP access to trusted entities only.

Long-Term Security Practices

Regularly update and patch network devices to protect against known vulnerabilities.
Implement network segmentation to limit the impact of potential attacks.
Conduct regular security audits and assessments to identify and address security weaknesses.

Patching and Updates

Cisco has released patches to address the vulnerability. Ensure timely application of these patches to secure the affected systems.