{"id":"CVE-2017-12231","published":"2017-09-29T01:34:48Z","modified":"2026-06-17T01:02:55Z","title":"Cisco IOS Software Network Address Translation Denial-of-Service Vulnerability","vendor":"Cisco","product":"IOS software","tier":"core","eol":null,"description":{"text":"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.","provenance":"source","from":"NVD"},"summary":{"text":"A flaw in the Network Address Translation implementation of Cisco IOS software, in the NAT application layer gateway that translates H.323 Registration, Admission, and Status (RAS) messages, causes improper handling of those messages. An unauthenticated, remote attacker can send a crafted H.323 RAS packet over IPv4 through an affected device, crashing and reloading it to cause a denial of service, provided the device is configured to use NAT ALG for H.323 RAS messages, which is enabled by default.","provenance":"ai","model":"claude-haiku-5-5","generatedAt":"2026-10-23T07:13:47Z"},"cvss":{"score":7.5,"severity":"HIGH","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","provenance":"source","from":"NVD"},"epss":{"score":0.0707,"percentile":0.9419,"date":"2026-10-28","provenance":"source"},"kev":{"dateAdded":"2022-03-03","dueDate":"2022-03-24","ransomware":false,"requiredAction":"Apply updates per vendor instructions.","notes":"https://nvd.nist.gov/vuln/detail/CVE-2017-12231","provenance":"source"},"vulncheckKev":{"dateAdded":"2022-03-03","exploitedFirstSeen":"2022-03-03","ransomware":false,"evidence":[{"url":"https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json","date":"2022-03-03"},{"url":"https://www.cisco.com/c/en/us/support/docs/csa/cisco-sa-20170927-nat.html","date":"2022-12-16"}],"evidenceTotal":2,"provenance":"source"},"exploited":true,"otx":{"pulseCount":50,"pulses":[{"name":"Actively_Exploited_Kev | Oct 29, 2026","url":"https://otx.alienvault.com/pulse/6ae20c1db17e7057ae7d9ad1","created":"2026-10-28"},{"name":"Actively_Exploited_Kev | Oct 28, 2026","url":"https://otx.alienvault.com/pulse/6ae0ba7e0e2a97ff7b218819","created":"2026-10-27"},{"name":"Actively_Exploited_Kev | Oct 27, 2026","url":"https://otx.alienvault.com/pulse/6adf68b85c3e852f3c111d18","created":"2026-10-26"},{"name":"Actively_Exploited_Kev | Oct 24, 2026","url":"https://otx.alienvault.com/pulse/6adb740e397c3ad4799aa4cd","created":"2026-10-23"},{"name":"Actively_Exploited_Kev | Oct 23, 2026","url":"https://otx.alienvault.com/pulse/6ada236fcfba2dfa730ea482","created":"2026-10-22"},{"name":"Actively_Exploited_Kev | Oct 22, 2026","url":"https://otx.alienvault.com/pulse/6ad8d33a077cbb5cab524d80","created":"2026-10-21"},{"name":"Actively_Exploited_Kev | Oct 21, 2026","url":"https://otx.alienvault.com/pulse/6ad78130c4d1ac2be83a8b6d","created":"2026-10-20"},{"name":"Actively_Exploited_Kev | Oct 20, 2026","url":"https://otx.alienvault.com/pulse/6ad62f63c24a405a3423cc13","created":"2026-10-19"},{"name":"Actively_Exploited_Kev | Oct 19, 2026","url":"https://otx.alienvault.com/pulse/6ad4dda174e5797d0bd238b7","created":"2026-10-18"},{"name":"Actively_Exploited_Kev | Oct 18, 2026","url":"https://otx.alienvault.com/pulse/6ad38c22e1848f8189d1c121","created":"2026-10-17"}],"provenance":"machine"},"cwes":[{"id":"CWE-399","name":null}],"references":[{"url":"http://www.securityfocus.com/bid/101039","tags":["Broken Link","Third Party Advisory","VDB Entry"]},{"url":"http://www.securitytracker.com/id/1039449","tags":["Broken Link","Third Party Advisory","VDB Entry"]},{"url":"https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170927-nat","tags":["Vendor Advisory"]},{"url":"http://www.securityfocus.com/bid/101039","tags":["Broken Link","Third Party Advisory","VDB Entry"]},{"url":"http://www.securitytracker.com/id/1039449","tags":["Broken Link","Third Party Advisory","VDB Entry"]},{"url":"https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170927-nat","tags":["Vendor Advisory"]},{"url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2017-12231","tags":["US Government Resource"]}],"techniques":[{"id":"T1190","name":"Exploit Public-Facing Application","tactics":["initial-access"],"provenance":"ai","basis":"ai-mapping","bases":["ai-mapping"],"basisDetail":"claude-haiku-5-5: Remote crafted packet targets exposed network service","mappingType":"exploitation_technique","evidence":[{"from":"description","quote":"An attacker could exploit this vulnerability by sending a crafted H.323 RAS packet through an affected device","start":424,"end":533}],"model":"claude-haiku-5-5","confidence":"medium","confidenceNote":"AI-mapped from the description (quote-validated, not expert-reviewed)"},{"id":"T1499.004","name":"Application or System Exploitation","tactics":["impact"],"provenance":"ai","basis":"ai-mapping","bases":["ai-mapping"],"basisDetail":"claude-haiku-5-5: Crash and reload causes application or system DoS","mappingType":"primary_impact","evidence":[{"from":"description","quote":"cause the affected device to crash and reload, resulting in a DoS condition","start":584,"end":659}],"model":"claude-haiku-5-5","confidence":"medium","confidenceNote":"AI-mapped from the description (quote-validated, not expert-reviewed)"}],"reports":[],"affected":[],"advisories":[],"euvd":{"id":"EUVD-2017-3804","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2017-3804","exploited":true,"exploitedSince":"2022-03-03","provenance":"source"},"exploits":[],"exploitSources":null,"exploitRefs":[],"flow":[{"stage":"exploitation","techniques":["T1190"],"provenance":"ai"},{"stage":"primary","techniques":["T1499.004"],"provenance":"ai"}],"timeline":[{"date":"2017-09-29","kind":"published","label":"Published (NVD)","url":"https://nvd.nist.gov/vuln/detail/CVE-2017-12231","provenance":"source"},{"date":"2022-03-03","kind":"exploited-reported","label":"Exploitation first reported (VulnCheck KEV evidence)","url":"https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json","provenance":"source"},{"date":"2022-03-03","kind":"kev","label":"Added to CISA KEV","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","provenance":"source"},{"date":"2022-03-03","kind":"euvd-exploited","label":"ENISA EUVD: exploited","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2017-3804","provenance":"source"}],"speed":{"daysToPublicExploit":null,"firstExploitFrom":null,"daysToKev":1616},"priority":{"score":62.1,"factors":[{"name":"In a KEV catalog","points":35.0,"detail":"listed in CISA KEV and VulnCheck KEV"},{"name":"Recent KEV listing","points":0.0,"detail":"added 1701 days ago"},{"name":"Known ransomware use","points":0.0,"detail":"not known"},{"name":"EPSS percentile","points":18.84,"detail":"percentile 0.9419"},{"name":"Named in threat reports","points":0.0,"detail":"0 reports"},{"name":"Public exploit code","points":0.0,"detail":"none found"},{"name":"Mentioned in OTX pulses","points":3.0,"detail":"50 pulses"},{"name":"CVSS severity","points":5.25,"detail":"base score 7.5"},{"name":"End-of-life product","points":0.0,"detail":"supported or unknown"}]}}