Threats / Cisco / CVE-2017-12234
CVE-2017-12234
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-06-22
Cisco IOS software vulnerability
A vulnerability in Cisco IOS Common Industrial Protocol (CIP) implementation allows unauthenticated remote attackers to cause device reload, resulting in denial of service.
Verdict
Today item — known-exploited.
An unauthenticated remote attacker can exploit improper input validation in CIP handling to trigger a device crash. This vulnerability has been observed in active exploitation and affects Cisco IOS devices without authentication requirements.
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 0.06938 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
Affected: Cisco, IOS software. Confirm exact fixed builds in the vendor advisory.
Weakness (CWE)
Mapped to CWE-20 Improper Input Validation.CWE assignment from the public NVD record; the weakness class drives how the flaw is exploited.
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 a malformed CIP packet to the target Cisco IOS device.
Business
The device becomes unavailable as it reloads, disrupting network operations and services dependent on that infrastructure.
2
Keys to the kingdom — privilege/identity takeover narrative 2
Attacker
I repeat the attack to maintain continuous denial of service against the affected device.
Business
Sustained outages degrade operational resilience and increase incident response costs.
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