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CVE-2017-12231

A vulnerability in the implementation of Network Address Translation (NAT) functionality in Cisco IOS 12.4 through 15.6 could allow an…

High7.5Known exploitedEPSS 7.1%
Published
Updated
Reserved
Assigned by
cisco

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.

Exploited in the wild

CISA lists this vulnerability in its Known Exploited Vulnerabilities catalog as Cisco IOS Software Network Address Translation Denial-of-Service Vulnerability.

Added
3 Mar 2022
Fix due (US federal)
24 Mar 2022
Used by ransomware
Not known

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Scores

CVSS scores of CVE-2017-12231, by who scored it
Scored byCVSSScoreVector
CISA-ADPADP (enrichment)3.1High7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVDNVD · Analyzed3.1High7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS (exploitation in 30 days)
7.1% · top 5.8% of all CVEs (4 Nov 2026)
CISA SSVC
Exploitation: active · Automatable: yes · Technical impact: partial
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The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.5.

Weakness

Affected products

  • Cisco IOS

    • affected Cisco IOS

References (4)

Sources

The same CVE in the primary databases and aggregators, to check against.

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Record last updated .