{"cve":"CVE-2018-0421","nvd":{"published":"2018-10-05T14:29:00.623","modified":"2026-06-17T01:30:44.977","status":"Modified","description":"A vulnerability in TCP connection management in Cisco Prime Access Registrar could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition when the application unexpectedly restarts. The vulnerability is due to incorrect handling of incoming TCP SYN packets to specific listening ports. The improper handling of the TCP SYN packets could cause a system file description to be allocated and not freed. An attacker could exploit this vulnerability by sending a crafted stream of TCP SYN packets to the application. A successful exploit could allow the attacker to cause the application to eventually restart if a file description cannot be obtained.","cvss_v4":null,"cvss_v3":{"version":"3.0","vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H","score":8.6},"cwes":["CWE-772","CWE-399"],"references":["http://www.securityfocus.com/bid/105282","http://www.securitytracker.com/id/1041684","https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180905-cpar-dos","http://www.securityfocus.com/bid/105282","http://www.securitytracker.com/id/1041684"],"products":["cisco:prime_access_registrar","cisco:prime_access_registrar_jumpstart"],"source":"nvd","synced_at":"2026-10-19T20:53:14.491561039+00:00"},"epss":{"cve":"CVE-2018-0421","score":0.0348,"percentile":0.89109,"date":"2026-10-31"},"kev":null,"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."]}