Threats / Cisco / CVE-2017-12232
CVE-2017-12232
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-06-22
Cisco IOS software vulnerability
A protocol implementation vulnerability in Cisco IOS on ISR G2 routers allows unauthenticated adjacent attackers to trigger device reload, causing denial of service.
Verdict
Today item — known-exploited.
An adjacent attacker can exploit a protocol handling flaw to crash affected Cisco ISR G2 routers without authentication. The vulnerability has been observed in active exploitation. Impact is limited to availability.
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 0.02171 — 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-399 Resource Management Errors — weakness family: Resource / availability.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 a malicious protocol message and send it to an adjacent network segment where the target router operates.
Business
Network availability is disrupted as the router reloads unexpectedly, interrupting traffic forwarding and services dependent on that device.
2
Keys to the kingdom — privilege/identity takeover narrative 2
Attacker
I repeatedly trigger the vulnerability to cause sustained device instability and repeated outages.
Business
Operational costs increase due to unplanned maintenance, troubleshooting effort, and potential SLA violations with customers relying on continuous connectivity.
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