Cyber Resilience

CVE-2017-12231

Cisco Ios 12.4 – 15.6

CISA KEVActive ExploitationEUVD Exploited
Published
29 September 2017
Modified
21 April 2026
KEV Added
03 March 2022
Patch / advisory
CVSS Score v3.1 7.5
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.071 94th percentile
Risk Priority 84 floored blend · peak EPSS

Summary

CVE-2017-12231 is a high-severity an unspecified weakness vulnerability in Cisco Asr 9010. Its CVSS base score is 7.5 (High).

Operationally, ranked in the top 6% of CVEs by exploit likelihood; CISA has added it to the Known Exploited Vulnerabilities catalog.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

A vulnerability in the Network Address Translation (NAT) implementation within Cisco IOS versions 12.4 through 15.6 could permit an unauthenticated remote attacker to trigger a denial of service condition. The flaw stems from improper translation of H.323 messages that rely on the Registration, Admission, and Status (RAS) protocol when those messages arrive via IPv4. It affects devices configured for NAT application layer gateway (ALG) processing of H.323 RAS traffic, a capability enabled by default, and is tracked under Cisco Bug ID CSCvc57217.

An attacker can exploit the issue by sending a specially crafted H.323 RAS packet through an affected device. Successful exploitation causes the device to crash and reload, producing a denial of service. The attack requires no authentication or user interaction and is rated 7.5 on the CVSS 3.1 scale with a high impact on availability.

The referenced Cisco Security Advisory cisco-sa-20170927-nat provides official guidance on addressing the vulnerability.

EU & UK References

Vulnerability Data

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…

more

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.

CWE(s)
KEV Date Added
03 March 2022

Related Threats

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CVE-2017-12232Same product: Cisco 1100-4G\/6G Integrated Services Routerboth on KEV
CVE-2018-0161Same product: Cisco Iosboth on KEV
CVE-2017-12238Same product: Cisco Iosboth on KEV
CVE-2017-12319Same product: Cisco 1100-4G\/6G Integrated Services Routerboth on KEV
CVE-2023-20273Same product: Cisco Catalyst 3650both on KEV

Affected Assets

cisco
ios
12.4 — 15.6

Mitigating Controls

No mitigating controls mapped yet. The per-CVE control annotator has not reached this CVE.

References