Reference page — cumulative record through Thursday, October 8, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2017-12231

CVE-2017-12231HIGH

n/a Cisco IOS — Cisco IOS software

  AV  AC  PR  UI  S  C  I  A   CVSS    EPSS   %ile   KEV
   N   L   N   N  U  N  N  H    7.5   .0707   94.1   YES

AFFECTED
  Product    Versions     Fixed
  Cisco IOS  Cisco IOS –  —

TIMELINE
  Aug 3   Reserved by cisco
  Sep 28  Published (CNA: cisco)
  Mar 3   Added to CISA KEV, remediation due 2022-03-24

CWE-399 · CNA: cisco · CVSS v3.1 · 4 references · KEV due March 24, 2022

Description

A vulnerability in the implementation of Network Address Translation (NAT) functionality in Cisco IOS 12.4 through 15.6 could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to the improper translation of H.323 messages that use the Registration, Admission, and Status (RAS) protocol and are sent to an affected device via IPv4 packets. An attacker could exploit this vulnerability by sending a crafted H.323 RAS packet through an affected device. A successful exploit could allow the attacker to cause the affected device to crash and reload, resulting in a DoS condition. This vulnerability affects Cisco devices that are configured to use an application layer gateway with NAT (NAT ALG) for H.323 RAS messages. By default, a NAT ALG is enabled for H.323 RAS messages. Cisco Bug IDs: CSCvc57217.

Lifecycle

Complete event history — 3 events, chronological
Date	Event	Detail
August 3, 2017	Reserved	Reserved by cisco
September 28, 2017	Published	Published (CNA: cisco)
March 3, 2022	KEV ADDED	Added to CISA KEV, remediation due 2022-03-24

Affected

Affected products and packages — 1 row
Vendor	Product / Package	Ecosystem	Version introduced	Fixed
n/a	Cisco IOS	—	Cisco IOS	—

Weaknesses

CWE-399

References (4)

http://www.securityfocus.com/bid/101039 [vdb-entry, x_refsource_BID]
http://www.securitytracker.com/id/1039449 [vdb-entry, x_refsource_SECTRACK]
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170927-nat [x_refsource_CONFIRM]
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2017-12231 [government-resource]

Authoritative record: CVE-2017-12231 at cve.org

Weaknesses: CWE-399

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2017-12231 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Thursday, October 8, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.