CVE-2018-0209 in 550X Series Stackable Managed Switch
Summary
by MITRE
A vulnerability in the Simple Network Management Protocol (SNMP) subsystem communication channel through the Cisco 550X Series Stackable Managed Switches could allow an authenticated, remote attacker to cause the device to reload unexpectedly, causing a denial of service (DoS) condition. The device nay need to be manually reloaded to recover. The vulnerability is due to lack of proper input throttling of ingress SNMP traffic over an internal interface. An attacker could exploit this vulnerability by sending a crafted, heavy stream of SNMP traffic to the targeted device. An exploit could allow the attacker to cause the device to reload unexpectedly, causing a DoS condition. Cisco Bug IDs: CSCvg22135.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 01/11/2020
The vulnerability identified as CVE-2018-0209 affects Cisco 550X Series Stackable Managed Switches and represents a significant denial of service weakness within the Simple Network Management Protocol (SNMP) subsystem. This flaw exists in the communication channel handling mechanism that processes incoming SNMP traffic through internal interfaces, creating a pathway for authenticated remote attackers to disrupt network operations. The vulnerability specifically manifests when the device fails to implement adequate input throttling measures for ingress SNMP traffic, allowing malicious actors to overwhelm the system with crafted traffic streams that trigger unexpected device reloads.
The technical exploitation of this vulnerability requires an authenticated attacker who can send a deliberately crafted and heavy stream of SNMP traffic to the targeted switch device. This attack vector leverages the insufficient traffic management within the SNMP subsystem's internal communication channels, where proper input validation and rate limiting mechanisms are absent or inadequate. The flaw essentially allows an attacker to flood the switch's SNMP processing capabilities with excessive traffic volumes, causing the device to become unresponsive and ultimately requiring a manual reload to restore normal operations. This type of vulnerability directly impacts the availability aspect of network security, as it can be used to systematically disrupt network management and monitoring capabilities that depend on SNMP communication.
The operational impact of CVE-2018-0209 extends beyond simple service disruption, as it can severely compromise network management infrastructure and monitoring capabilities. When switches reload unexpectedly due to this vulnerability, network administrators lose visibility into their network devices, potentially causing extended periods of network monitoring gaps that could mask other security incidents. The need for manual intervention to restore device functionality creates operational overhead and increases the risk of extended downtime during critical network maintenance windows. This vulnerability particularly affects enterprise environments where network management systems rely heavily on SNMP for device monitoring, configuration management, and performance tracking, making the potential for cascading failures across multiple network devices more likely.
Organizations should implement multiple layers of mitigation strategies to address this vulnerability, including network segmentation to limit access to SNMP interfaces, implementation of SNMP access control lists, and regular monitoring of SNMP traffic patterns for anomalous activity. The vulnerability aligns with CWE-310, which addresses cryptographic weaknesses, and can be mapped to ATT&CK technique T1499.004 for network denial of service attacks. Network administrators should ensure that SNMPv3 is properly configured with strong authentication and encryption mechanisms, while also implementing rate limiting and traffic monitoring solutions to detect and prevent the exploitation patterns associated with this vulnerability. Additionally, regular security updates and firmware patches from Cisco should be deployed promptly to address the underlying implementation flaws in the SNMP subsystem that enable this attack vector.