CVE-2018-0161 Explained : Impact and Mitigation
Learn about CVE-2018-0161 affecting Cisco Catalyst Switches running Cisco IOS Software. Find out how an attacker can exploit SNMP to cause a denial of service (DoS) condition and the mitigation steps.
Cisco Catalyst Switches running Cisco IOS Software have a vulnerability in the SNMP subsystem, allowing an attacker to cause a denial of service (DoS) condition.
Understanding CVE-2018-0161
Certain models of Cisco Catalyst Switches running Cisco IOS Software are affected by a vulnerability in the Simple Network Management Protocol (SNMP) subsystem.
What is CVE-2018-0161?
- An authenticated, remote attacker can exploit this vulnerability to trigger a denial of service (DoS) condition by issuing an SNMP GET request for the ciscoFlashMIB OID on an affected device.
- The vulnerability impacts Cisco devices running vulnerable versions of Cisco IOS Software with SNMP Version 2 (SNMPv2) or SNMP Version 3 (SNMPv3) configured.
The Impact of CVE-2018-0161
- Successful exploitation could lead to the affected device restarting due to a SYS-3-CPUHOG.
- Affected devices include Cisco Catalyst 2960-L Series Switches, Cisco Catalyst Digital Building Series Switches 8P, and Cisco Catalyst Digital Building Series Switches 8U.
Technical Details of CVE-2018-0161
The technical details of the vulnerability are as follows:
Vulnerability Description
- A vulnerability in the SNMP subsystem of Cisco IOS Software on certain models of Cisco Catalyst Switches.
- Triggered when the software processes an SNMP read request for the ciscoFlashMIB OID.
Affected Systems and Versions
- Cisco Catalyst 2960-L Series Switches
- Cisco Catalyst Digital Building Series Switches 8P
- Cisco Catalyst Digital Building Series Switches 8U
Exploitation Mechanism
- An attacker can exploit the vulnerability by issuing an SNMP GET request for the ciscoFlashMIB OID on an affected device.
Mitigation and Prevention
Steps to mitigate and prevent the vulnerability:
Immediate Steps to Take
- Disable SNMP if not required or restrict access to trusted sources.
- Apply the necessary updates and patches provided by Cisco.
Long-Term Security Practices
- Regularly monitor and update SNMP configurations.
- Implement network segmentation to limit the impact of potential attacks.
- Stay informed about security advisories and best practices.
Patching and Updates
- Cisco has released patches to address this vulnerability. Ensure timely application of these patches to secure the affected systems.