{"id":"CVE-2009-0635","aliases":["EUVD-2009-0638","GHSA-jrx8-5mjp-vjpm"],"status":"published","title":"Memory leak in the Cisco Tunneling Control Protocol (cTCP) encapsulation feature in Cisco IOS 12...","description":"Memory leak in the Cisco Tunneling Control Protocol (cTCP) encapsulation feature in Cisco IOS 12.4, when an Easy VPN (aka EZVPN) server is enabled, allows remote attackers to cause a denial of service (memory consumption and device crash) via a sequence of TCP packets.","severity":{"version":"2.0","score":7.1,"vector":"AV:N/AC:M/Au:N/C:N/I:N/A:C","level":"high","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-09","score":0.02508,"percentile":0.8487,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-399"],"published":"2009-03-27T16:00:00Z","modified":"2026-06-16T23:05:27Z","products":[{"vendor":"cisco","product":"ios"}],"references":[{"url":"http://www.cisco.com/en/US/products/products_security_advisory09186a0080a90469.shtml","tags":["x_refsource_CONFIRM","x_transferred","Patch","Vendor Advisory"]},{"url":"http://www.cisco.com/en/US/products/products_security_advisory09186a0080a90459.shtml","tags":["vendor-advisory","x_refsource_CISCO","x_transferred","Patch","Vendor Advisory"]},{"url":"http://secunia.com/advisories/34438","tags":["third-party-advisory","x_refsource_SECUNIA","x_transferred","Vendor Advisory"]},{"url":"http://www.securityfocus.com/bid/34246","tags":["vdb-entry","x_refsource_BID","x_transferred"]},{"url":"https://exchange.xforce.ibmcloud.com/vulnerabilities/49417","tags":["vdb-entry","x_refsource_XF","x_transferred"]},{"url":"http://www.securitytracker.com/id?1021895","tags":["vdb-entry","x_refsource_SECTRACK","x_transferred"]},{"url":"http://www.vupen.com/english/advisories/2009/0851","tags":["vdb-entry","x_refsource_VUPEN","x_transferred","Vendor Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2009-0635"},{"url":"https://github.com/advisories/GHSA-jrx8-5mjp-vjpm"}],"sources":{"cve":[{"id":"CVE-2009-0635","description":"Memory leak in the Cisco Tunneling Control Protocol (cTCP) encapsulation feature in Cisco IOS 12.4, when an Easy VPN (aka EZVPN) server is enabled, allows remote attackers to cause a denial of service (memory consumption and device crash) via a sequence of TCP packets.","status":"published","published":"2009-03-27T16:00:00Z","modified":"2024-08-07T04:40:05.127Z","updated_at":"2026-11-02T14:33:26.302774Z"}],"euvd":[{"id":"EUVD-2009-0638","description":"Memory leak in the Cisco Tunneling Control Protocol (cTCP) encapsulation feature in Cisco IOS 12.4, when an Easy VPN (aka EZVPN) server is enabled, allows remote attackers to cause a denial of service (memory consumption and device crash) via a sequence of TCP packets.","status":"published","published":"2009-03-27T16:00:00Z","modified":"2024-08-07T04:40:05Z","updated_at":"2026-11-03T01:39:25.189813Z"}],"ghsa":[{"id":"GHSA-jrx8-5mjp-vjpm","title":"Memory leak in the Cisco Tunneling Control Protocol (cTCP) encapsulation feature in Cisco IOS 12...","description":"Memory leak in the Cisco Tunneling Control Protocol (cTCP) encapsulation feature in Cisco IOS 12.4, when an Easy VPN (aka EZVPN) server is enabled, allows remote attackers to cause a denial of service (memory consumption and device crash) via a sequence of TCP packets.","status":"published","published":"2022-05-02T03:17:02Z","modified":"2023-01-31T05:06:51Z","updated_at":"2026-11-02T14:49:06.344022Z"}],"nvd":[{"id":"CVE-2009-0635","description":"Memory leak in the Cisco Tunneling Control Protocol (cTCP) encapsulation feature in Cisco IOS 12.4, when an Easy VPN (aka EZVPN) server is enabled, allows remote attackers to cause a denial of service (memory consumption and device crash) via a sequence of TCP packets.","status":"published","published":"2009-03-27T16:30:02.077Z","modified":"2026-06-16T23:05:27.873Z","cvss":[{"version":"2.0","score":7.1,"vector":"AV:N/AC:M/Au:N/C:N/I:N/A:C","level":"high","assessor":"primary"}],"cwes":["CWE-399"],"updated_at":"2026-11-02T14:01:34.44527Z"}]}}