{"cve":"CVE-2017-12231","nvd":{"published":"2017-09-29T01:34:48.747","modified":"2026-06-17T01:02:55.660","status":"Analyzed","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_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","score":7.5},"cwes":["CWE-399"],"references":["http://www.securityfocus.com/bid/101039","http://www.securitytracker.com/id/1039449","https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170927-nat","http://www.securityfocus.com/bid/101039","http://www.securitytracker.com/id/1039449"],"products":["cisco:ios"],"source":"nvd","synced_at":"2026-10-19T20:46:01.145313090+00:00"},"epss":{"cve":"CVE-2017-12231","score":0.0707,"percentile":0.94215,"date":"2026-10-31"},"kev":{"cve":"CVE-2017-12231","date_added":"2022-03-03","due_date":"2022-03-24","vendor":"Cisco","product":"IOS software","known_ransomware":false},"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}