CVE-2018-0155: Cisco Catalyst Bidirectional Forwarding Detection Denial-of-Service Vulnerability

Vulnerability summary

CVE-2018-0155 is a high (CVSS 8.6) 7PK - Errors vulnerability in Cisco Catalyst 4500 Series Switches and Cisco Catalyst 4500-X Series Switches. It is known to be exploited: CISA lists it, first on 03-03-2022. EPSS estimates a 7.74% chance of exploitation in the next 30 days, higher than 94.5% of scored vulnerabilities.

Timeline

1. 28-03-2018
   PublishedVulnerability first disclosed.
2. 03-03-2022
   Added to CISA KEVCisco Catalyst Bidirectional Forwarding Detection Denial-of-Service Vulnerability
3. 17-03-2022
   CISA remediation dueApply updates per vendor instructions.
4. 12-01-2026
   Last modifiedVulnerability information updated.

Description

A vulnerability in the Bidirectional Forwarding Detection (BFD) offload implementation of Cisco Catalyst 4500 Series Switches and Cisco Catalyst 4500-X Series Switches could allow an unauthenticated, remote attacker to cause a crash of the iosd process, causing a denial of service (DoS) condition. The vulnerability is due to insufficient error handling when the BFD header in a BFD packet is incomplete. An attacker could exploit this vulnerability by sending a crafted BFD message to or across an affected switch. A successful exploit could allow the attacker to trigger a reload of the system. This vulnerability affects Catalyst 4500 Supervisor Engine 6-E (K5), Catalyst 4500 Supervisor Engine 6L-E (K10), Catalyst 4500 Supervisor Engine 7-E (K10), Catalyst 4500 Supervisor Engine 7L-E (K10), Catalyst 4500E Supervisor Engine 8-E (K10), Catalyst 4500E Supervisor Engine 8L-E (K10), Catalyst 4500E Supervisor Engine 9-E (K10), Catalyst 4500-X Series Switches (K10), Catalyst 4900M Switch (K5), Catalyst 4948E Ethernet Switch (K5). Cisco Bug IDs: CSCvc40729.

• CWE-3887PK - ErrorsThis category represents one of the phyla in the Seven Pernicious Kingdoms vulnerability classification. It includes weaknesses that occur when an application does not properly handle errors that occur during processing. According to the authors of the Seven Pernicious Kingdoms, "Errors and error handling represent a class of API. Errors related to error handling are so common that they deserve a special kingdom of their own. As with 'API Abuse,' there are two ways to introduce an error-related security vulnerability: the most common one is handling errors poorly (or not at all). The second is producing errors that either give out too much information (to possible attackers) or are difficult to handle."
• CWE-755Improper Handling of Exceptional ConditionsThe product does not handle or incorrectly handles an exceptional condition.