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UK Cyber Defence
VulnerabilityAnalyzed

CVE-2017-12231

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

KEVHIGH 7.5EPSS 7.13%

Does this matter?

Known to be exploited in the wild (CISA KEV, CISA remediation deadline 24 March 2022). Treat as an emergency change: patch or isolate now, then hunt for prior compromise.

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.

CVSS 3.1
7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS
7.13% probability · 94th percentile
CISA KEV
Listed 3 March 2022 · due 24 March 2022
Weakness
CWE-399
Affected
cisco/ios
Source
psirt@cisco.com

CISA notes

Apply updates per vendor instructions. https://nvd.nist.gov/vuln/detail/CVE-2017-12231

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.