Threats / Cisco / CVE-2018-0155
CVE-2018-0155
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-06-22
Cisco Catalyst 4500 Series Switches and 4500-X vulnerability
A vulnerability in BFD offload implementation on Cisco Catalyst 4500 Series Switches allows unauthenticated remote attackers to crash the iosd process, causing denial of service.
Verdict
Today item — known-exploited.
Unauthenticated remote attackers can exploit improper input validation in BFD processing to trigger a process crash on affected Catalyst switches, disrupting network operations without requiring credentials or authentication.
01
Is it exploitable?
— the evidence, ranked above the scoreReported exploitation
2 independent public reports of in-the-wild exploitation are cataloged.Distinct reporting sources (vendor, incident response, government); open them for the underlying claims.
Exploited in the wild
Listed in the CISA Known Exploited Vulnerabilities catalog (added 2022-03-03).
Probability (EPSS)
EPSS 0.07747 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
Affected: Cisco, Catalyst 4500 Series Switches and Cisco Catalyst 4500-X Series Switches. Confirm exact fixed builds in the vendor advisory.
Weakness (CWE)
Mapped to CWE-388 CWE-388.CWE assignment from the public NVD record; the weakness class drives how the flaw is exploited.
WeaknessCWE-388 · CWE-388
02
Who’s exploiting it?
— attribution turns risk into urgencyAttribution not established
No confirmed (advisory-backed) threat-actor attribution is established for this record. Absence of a named actor is not absence of compromise — see Coverage & confidence.
03
Why it matters
— the attack path, told twice: adversary, then board1
Front door — unauthenticated access narrative 1
Attacker
I craft and send malformed BFD packets to the target switch from the network.
Business
Network availability is disrupted as the iosd process crashes, causing the switch to become unresponsive.
2
Keys to the kingdom — privilege/identity takeover narrative 2
Attacker
I repeat the attack to maintain the denial-of-service condition across the affected infrastructure.
Business
Sustained outages impact business continuity, customer connectivity, and operational efficiency of network services.
04
What to do
— defensible action- Remediate per the vendor advisory — confirm the fixed build for your version and verify exposure.1
Say it to the boardA vulnerability with this evidence profile is a defensible budget line, not a backlog ticket — fund the change against the proof above.
05