ACTIVELY EXPLOITED

CVE-2017-12231: Cisco IOS Software Network Address Translation Denial-of-Service Vulnerability

Facts
VendorCisco
ProductIOS software
Actively exploitedYes
Added to CISA KEV3 Mar 2022
CISA federal deadline24 Mar 2022
Weakness (CWE)CWE-399

Required action (CISA's text)

Apply updates per vendor instructions.

Description (NVD)

A vulnerability in the implementation of Network Address Translation (NAT) functionality in Cisco IOS could allow an unauthenticated, remote attacker to cause a denial of service.

SOURCES

Other Cisco flaws

Data from NVD, CISA KEV, FIRST EPSS and vendor advisories. Updated 10 Nov 2026.