CVEvulnerability

CVE-2017-12231

7.5 HIGH Known exploited Published 2017-09-29 Modified 2026-06-17 Official page ↗

CISA Known Exploited Vulnerability

Cisco IOS Software Network Address Translation Denial-of-Service Vulnerability — Cisco IOS software

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.

Added to KEV: 2022-03-03
Remediation due: 2022-03-24
Ransomware use: Unknown
Required action: Apply updates per vendor instructions.
Notes: https://nvd.nist.gov/vuln/detail/CVE-2017-12231

Status: Analyzed
Published: 2017-09-29
Last modified: 2026-06-17
Assigner: [email protected]
CVSS 3.1 ([email protected]): 7.5 HIGH — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS 3.1 (134c704f-9b21-4f2e-91b3-4a467353bcc0): 7.5 HIGH — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS 2.0 ([email protected]): 7.8 HIGH — AV:N/AC:L/Au:N/C:N/I:N/A:C
Weaknesses: CWE-399

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.

Affected configurations

• cisco ios (>= 12.4 <= 15.6)

Weakness · not in database (1)

CWE-399

References