Threats / Cisco / CVE-2017-12238
CVE-2017-12238
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-08-04
Cisco Catalyst 6800 Series Switches vulnerability
A vulnerability in VPLS code of Cisco IOS for Catalyst 6800 Series Switches allows an unauthenticated, adjacent attacker to cause denial of service.
Verdict
Today item — known-exploited.
An adjacent network attacker can trigger a denial of service condition in affected Catalyst 6800 switches by exploiting a flaw in VPLS processing, disrupting network availability without requiring authentication.
CISA KEV Yes · 2022-03-035EPSS 0.02034 (verify live)6CVSS 6.5 (CISA)4CISA SSVC Exploitation: active · Automatable: no · Impact: partial4
01
Is it exploitable?
— the evidence, ranked above the scoreReported exploitation
1 independent public report 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 0.02034 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
CVSS 6.5 (CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H) · Affected: Cisco, Catalyst 6800 Series Switches. 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 1617 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 VPLS packet and send it from an adjacent network segment to the target switch.
Business
Network availability is disrupted as the switch becomes unresponsive, impacting business continuity and customer connectivity.
2
Keys to the kingdom — privilege/identity takeover narrative 2
Attacker
I trigger a crash or resource exhaustion in the switch's VPLS processing engine, forcing it offline.
Business
Critical infrastructure dependent on the switch experiences downtime, resulting in revenue loss and reputational damage.
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