CVE-2018-0155

A vulnerability in the Bidirectional Forwarding Detection (BFD) offload implementation of Cisco Catalyst 4500 Series Switches and Cisco Catalyst…

Browse: All 2018 CVEs · All vendors

CVSS score
8.6 High
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
CISA KEV
Yes — actively exploited (added 2022-03-03, remediation due 2022-03-17)
Weakness (CWE)
CWE-388, CWE-755
Published
2018-03-28
Last modified
2026-06-17
NVD status
Analyzed

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.

Affected products

Affected ranges per NVD CPE data; confirm exact versions in the vendor advisory.

Required action (CISA)

Apply updates per vendor instructions. Federal remediation deadline: 2022-03-17.

How to prioritize this

This vulnerability is on the CISA KEV list, meaning it is being actively exploited — treat it as urgent regardless of the raw CVSS number. Use the live CVE lookup for the latest NVD data, and the CVSS 3.1 calculator to model your own environmental score. For the actively exploited vulnerabilities that matter this week, read The Exploit HQ daily security brief.

References

FAQ

Is CVE-2018-0155 actively exploited?

Yes. CISA added CVE-2018-0155 to its Known Exploited Vulnerabilities (KEV) catalog on 2022-03-03, with a federal remediation deadline of 2022-03-17. A KEV listing means real-world exploitation is confirmed, so patching this should be prioritized above many higher-CVSS bugs that aren't being exploited.

What is the CVSS score of CVE-2018-0155?

CVE-2018-0155 has a CVSS base score of 8.6 (High). Its vector string is CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H.

Related vulnerabilities

Data source: NVD & CISA KEV. Shown as-is; nothing added. Last generated from NVD data — re-check the live tool for updates.