Vulnerabilities
CVE-2018-0155 — Cisco Catalyst Bidirectional Forwarding Detection Denial-of-Service Vulnerability
CVE-2018-0155 · Cisco IOS and IOS XE · CVSS 8.6 · KEV
In brief
- Severity · CVSS
- High8.6CVSS 3.1, High
- EPSS
- 8%
- CISA KEV
- Known exploited, listed since 3 Mar 2022
- CERT-FR
- No advisory or alert referenced in the catalog
- Vendor
- Cisco
- Published · Modified
- ·
- Last verified
Summary
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.
Weakness: CWE-388, CWE-755
Title, description and the vendor's statements are quoted from the CVE record; a vendor's advisory is summarised in Patcharo's words, with a link.
Affected and fixed versions
Per product and release branch, as the vendor's CVE record and official advisory state them. A fixed release is shown only when a document names it: the vendor's, or CERT-FR's for Check Point, with its source.
Cisco IOS and IOS XE
- —Affected versionsCisco IOS and IOS XEFirst fixed releaseNot published in the sources followed
The vendor states fixes are available; the releases per branch are in its advisory.
Remediation
Fix available
Vendor fix
Cisco has released updates that fix this vulnerability; its advisory lists them.
SourceCisco Security Advisory cisco-sa-20180328-bfd· revised 15 Dec 2022
Workarounds (vendor)
Cisco states in its advisory that no workaround is available.
Last verified 1 Oct 2026 at 09:31 UTC
Known exploitation
Added to CISA KEV on 3 Mar 2022
Federal remediation due date: 17 Mar 2022
8% probability of exploitation in the next 30 days (percentile 94%).
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
CERT-FR
No CERT-FR advisory or alert of the last two years references this CVE, for the vendors Patcharo covers.
Timeline
- Published by the source
- Added to CISA KEV
- CISA remediation due date
- Source record last modified
- EPSS score computed
- Last verified by Patcharo
Official sources
- Cisco (CVE record)retrieved 1 Oct 2026 at 09:31 UTC
- CISA Known Exploited Vulnerabilitiesretrieved 1 Oct 2026 at 09:28 UTC
- NVDretrieved 27 Sept 2026 at 23:44 UTC
- FIRST EPSSretrieved 30 Sept 2026 at 00:17 UTC
- Cisco Security Advisory cisco-sa-20180328-bfdretrieved 1 Oct 2026 at 09:31 UTC
Vendor advisory
References
Cisco · CISA Known Exploited Vulnerabilities · NVD · FIRST EPSS · Cisco Security Advisory cisco-sa-20180328-bfd
How Patcharo reads this
Affected and fixed releases come from the vendor's structured statements and are matched against exact versions; CVSS from NVD, exploitation from CISA KEV and the vendor's own advisory, probability from FIRST EPSS. Missing data stays Unknown and never becomes Not affected.
Read the methodologyRead the guide: Cisco Secure Firewall release trains: Threat Defense, Management Center and ASA versions explained