CVE-2019-1806 Explained : Impact and Mitigation

A weakness has been identified in the input packet processor of Cisco Small Business Sx200, Sx300, Sx500, ESW2 Series Managed Switches and Small Business Sx250, Sx350, Sx550 Series Switches, related to the Simple Network Management Protocol (SNMP). An authenticated, remote attacker could take advantage of this vulnerability to disrupt the processing of traffic by the SNMP application on an affected device, leading to a complete utilization of the CPU. It may be necessary for the device to be manually restored to its normal state of operation. The vulnerability is a result of inadequate authentication of SNMP protocol data units (PDUs) within the SNMP packets. Exploiting this vulnerability involves sending a malevolent SNMP packet to a targeted device. If successfully exploited, the attacker could obstruct the traffic forwarding capability of the device, resulting in a denial of service (DoS) situation. Cisco has already released firmware updates that address this vulnerability.

Understanding CVE-2019-1806

This CVE pertains to a denial of service vulnerability in Cisco Small Business Series Switches related to the Simple Network Management Protocol (SNMP).

What is CVE-2019-1806?

The vulnerability allows an authenticated remote attacker to disrupt traffic processing by the SNMP application on affected devices, potentially leading to a complete CPU utilization.

The Impact of CVE-2019-1806

CVSS Score: 7.7 (High)
Attack Vector: Network
Availability Impact: High
The vulnerability could result in a denial of service (DoS) situation by obstructing traffic forwarding capability.

Technical Details of CVE-2019-1806

This section provides detailed technical information about the vulnerability.

Vulnerability Description

The vulnerability is due to inadequate authentication of SNMP protocol data units (PDUs) within SNMP packets.

Affected Systems and Versions

Affected Product: Cisco 550X Series Stackable Managed Switches
Vendor: Cisco
Vulnerable Versions:
Less than 1.4.10.6 (Custom version)
Less than 2.5.0.78 (Custom version)

Exploitation Mechanism

An attacker can exploit the vulnerability by sending a malicious SNMP packet to the targeted device, disrupting traffic processing.

Mitigation and Prevention

To address CVE-2019-1806, follow these mitigation strategies:

Immediate Steps to Take

Apply the firmware updates provided by Cisco to fix the vulnerability.
Monitor network traffic for any suspicious activity related to SNMP.

Long-Term Security Practices

Regularly update and patch network devices to prevent vulnerabilities.
Implement strong network access controls and authentication mechanisms.

Patching and Updates

Ensure all affected devices are updated with the latest firmware releases from Cisco to mitigate the vulnerability.