Threats / Cisco / CVE-2018-0161
CVE-2018-0161
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-08-04
Cisco IOS Software vulnerability
A vulnerability in the SNMP subsystem of Cisco IOS Software on certain Catalyst Switches allows an authenticated remote attacker to cause denial of service.
Verdict
Today item — known-exploited.
An authenticated remote attacker can exploit a resource exhaustion flaw in SNMP processing to crash or hang affected Catalyst Switches, disrupting network operations. The vulnerability has been observed in active exploitation.
CISA KEV Yes · 2022-03-035EPSS 0.04729 (verify live)6CVSS 6.3 (CISA)4CISA SSVC Exploitation: active · Automatable: no · Impact: partial4
01
Is it exploitable?
— the evidence, ranked above the scoreReported exploitation
3 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 0.04729 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
CVSS 6.3 (CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:N/I:N/A:H) · Affected: Cisco, IOS Software. Confirm exact fixed builds in the vendor advisory.CVSS — CISA-assigned via the ADP container (CVE.org), version 3.1; the CNA left no metrics, so CISA's own score is used ahead of NVD.
Weakness (CWE)
Mapped to CWE-399 Resource Management Errors — weakness family: Resource / availability.CWE — CNA-assigned (CVE.org); the weakness class drives how the flaw is exploited.
CISA SSVC (triage disposition)
Exploitation: active · Automatable: no · Technical Impact: partialCISA's own stakeholder-specific triage inputs, published in the CVE record (CISA Coordinator role). NOTE: this is CISA's three decision points; the final Act/Attend/Track decision also requires a Mission & Well-being input not published here, so no overall decision is asserted.
Currency of the record
CISA added this to its KEV catalog 1436 days after the CVE record was published.KEV lag = CISA-KEV dateAdded − CVE.org datePublished; a floor on how long the known-exploited flaw sat in the public record before the federal catalog listed it. Severity/weakness here is CNA- or CISA-assigned (current at disclosure), independent of NVD's analysis backlog.
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 a malicious SNMP request and send it to an authenticated session on the target switch.
Business
Network availability is compromised as the switch becomes unresponsive or crashes.
2
Keys to the kingdom — privilege/identity takeover narrative 2
Attacker
I trigger resource exhaustion in the SNMP subsystem, causing the device to enter a denial-of-service state.
Business
Critical infrastructure connectivity is lost, affecting dependent systems and services relying on the switch.
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