Exploited CVEs / Cisco / CVE-2017-12231
CVE-2017-12231
Cisco IOS Software Network Address Translation Denial-of-Service Vulnerability. Exploitation in the wild is confirmed by CISA, not predicted. Federal agencies were required to remediate by 2022-03-24 (that deadline has passed); treat that date as the outer bound for your own environment. The fix is in the vendor advisory: Cisco Security Advisories (PSIRT), linked below.
Actively exploited Cisco IOS software vulnerability, High severity, CVSS 7.5. Added to the CISA KEV catalog 2022-03-03.
Risk summary
Updated July 27, 2026. Data refreshed on every build from MSRC, CISA KEV, and FIRST EPSS.
Senserva AI Opinion for CVE-2017-12231
NAT is nearly universal on edge routers, and this flaw in the Cisco IOS NAT implementation lets an unauthenticated remote attacker cause a denial of service. Severity is High (CVSS 7.5), EPSS is 7%, and exploitation is confirmed per the 2022-03-03 KEV entry. Since the vulnerable feature sits directly in the packet path for internet traffic, exposure is inherent to the router's job.
Do this: Upgrade IOS on internet-edge routers performing NAT before addressing internal-only devices.
AI-generated from public data, 2026-07-07. Verify against the vendor advisory before acting.
Senserva AI Opinion and rich prompt for CVE-2017-12231
Copy this prompt into Claude, ChatGPT, or Copilot. The facts are included, sourced from this page.
Full tracking and change history for CVE-2017-12231
Published and last-revised dates are authoritative, from Microsoft MSRC (or the CISA KEV date-added). Senserva additionally records day-to-day changes from 2026-07-07, refreshed several times a day; the change count reflects that forward-only tracking.
CISA required action
Federal (BOD 22-01) remediation due date: 2022-03-24 (past due).
Apply updates per vendor instructions.
Official fix for CVE-2017-12231
The authoritative fix and affected-version list are published by the vendor. Find the IOS software advisory on Cisco Security Advisories (PSIRT).
Common questions about CVE-2017-12231
Is CVE-2017-12231 actively exploited?
Yes. CVE-2017-12231 was added to the CISA Known Exploited Vulnerabilities (KEV) catalog on 2022-03-03, which means exploitation in the wild has been confirmed, not predicted. Its EPSS 30-day exploitation probability is 7.1%.
What is the CISA deadline and required action for CVE-2017-12231?
CISA set the federal (BOD 22-01) remediation due date at 2022-03-24, which has passed; treat any unremediated system as overdue. The verbatim required action: Apply updates per vendor instructions.
What fixes CVE-2017-12231?
The authoritative fix is in the vendor advisory: see Cisco Security Advisories (PSIRT) for the patched IOS software versions and any workarounds. KEV listing makes this a fix-first item: patch it ahead of higher-CVSS issues nobody is exploiting.
Can I ask my own AI about CVE-2017-12231?
Yes. This page includes a free, ready-to-paste AI prompt containing CVE-2017-12231's key facts: severity, CVSS, EPSS, the KEV date, the CISA due date, and the required action. Copy it into Claude, ChatGPT, or Copilot; the data is refreshed twice a day (5 AM and 3 PM US Central).
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