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

Source: https://junglewise.ai/threats/cve-2017-12231-cisco-ios-software-network-address-translation-denial-of-service  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2022-03-03. Updated: 2026-05-10  
License: CC BY 4.0 with a link back

CVE-2017-12231 · Severity: critical · CVSS 7.5 · Exploited in the wild · Published 2022-03-03

A vulnerability in Cisco IOS NAT implementation allows remote attackers to cause a denial of service (device crash and reload) via crafted H.323 RAS packets. The issue stems from improper translation of H.323 messages using the Registration, Admission, and Status (RAS) protocol when NAT ALG is enabled.

Technologies: [Cisco IOS](https://junglewise.ai/threats/technologies/ios), [Cisco Ios Software](https://junglewise.ai/threats/technologies/ios-software), [Cisco IOS XE](https://junglewise.ai/threats/technologies/ios-xe). Vendors: [Cisco](https://junglewise.ai/threats/vendors/cisco).

## Quick answers

**Is CVE-2017-12231 exploited in the wild?** Yes. CVE-2017-12231 is known to be exploited in the wild, first recorded on 3 March 2022. Treat it as urgent.

**How severe is CVE-2017-12231?** Critical severity, with a CVSS score of 7.5, published 3 March 2022.

**Which products and versions are affected?** Cisco IOS 12.4 through 15.6.

**Is there a fix for CVE-2017-12231?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2017-12231 attacked?** It is attacked over the network, in an operating system.

**Am I affected by CVE-2017-12231?** Check whether you run Cisco IOS, Cisco Ios Software or Cisco IOS XE. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Affected products

- Cisco IOS 12.4 through 15.6

## Timeline

- 2017-09-27: disclosed: Initial Cisco advisory publication
- 2022-03-03: kev added: Added to CISA Known Exploited Vulnerabilities Catalog

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