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

Source: https://junglewise.ai/threats/cve-2018-0155-cisco-catalyst-bidirectional-forwarding-detection-denial-of  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2022-03-03. Updated: 2026-05-10  
License: CC BY 4.0 with a link back

CVE-2018-0155 · Severity: critical · CVSS 8.6 · Exploited in the wild · Published 2022-03-03

A vulnerability in the Bidirectional Forwarding Detection (BFD) offload implementation of Cisco Catalyst switches could allow an unauthenticated, remote attacker to cause a denial-of-service (DoS) condition. The flaw is due to insufficient error handling of incomplete BFD headers, which can be exploited by sending crafted BFD packets to trigger a reload of the system.

Vendors: [Cisco](https://junglewise.ai/threats/vendors/cisco).

## Quick answers

**Is CVE-2018-0155 exploited in the wild?** Yes. CVE-2018-0155 is known to be exploited in the wild, first recorded on 3 March 2022. Treat it as urgent.

**How severe is CVE-2018-0155?** Critical severity, with a CVSS score of 8.6, published 3 March 2022.

**Which products and versions are affected?** Cisco Catalyst 4500 Series Switches; Cisco Catalyst 4500-X Series Switches; Cisco Catalyst 4900M Switch; Cisco Catalyst 4948E Ethernet Switch; and 2 more.

**Is there a fix for CVE-2018-0155?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2018-0155 attacked?** It is attacked over the network, in an operating system.

**Am I affected by CVE-2018-0155?** Check whether you run Cisco Catalyst 4500 Series Switches, Cisco Catalyst 4500-X Series Switches or Cisco Catalyst 4500-X Series Switches. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Affected products

- Cisco Catalyst 4500 Series Switches
- Cisco Catalyst 4500-X Series Switches
- Cisco Catalyst 4900M Switch
- Cisco Catalyst 4948E Ethernet Switch
- Cisco IOS
- Cisco IOS XE

## Timeline

- 2018-03-28: advisory: Initial Cisco Security Advisory published
- 2022-03-03: kev added: Added to CISA Known Exploited Vulnerabilities Catalog
- 2022-03-03: disclosed: NVD publication date