{"id":"CVE-2015-4199","aliases":["EUVD-2015-4222","GHSA-3422-45qx-4m3x"],"status":"published","title":"Race condition in the IPv6-to-IPv4 functionality in Cisco IOS 15.3S in the Performance Routing...","description":"Race condition in the IPv6-to-IPv4 functionality in Cisco IOS 15.3S in the Performance Routing Engine (PRE) module on UBR devices allows remote attackers to cause a denial of service (NULL pointer free and module crash) by triggering intermittent connectivity with many IPv6 CPE devices, aka Bug ID CSCug47366.","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":"2026-11-08","score":0.02109,"percentile":0.81903,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-362"],"published":"2015-06-27T10:00:00Z","modified":"2026-06-17T00:26:54Z","products":[{"vendor":"cisco","product":"ios"}],"references":[{"url":"http://www.securitytracker.com/id/1032692","tags":["vdb-entry","x_refsource_SECTRACK","x_transferred","Third Party Advisory","VDB Entry"]},{"url":"http://tools.cisco.com/security/center/viewAlert.x?alertId=39423","tags":["vendor-advisory","x_refsource_CISCO","x_transferred","Vendor Advisory"]},{"url":"http://www.securityfocus.com/bid/75335","tags":["vdb-entry","x_refsource_BID","x_transferred","Third Party Advisory","VDB Entry"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2015-4199"},{"url":"https://github.com/advisories/GHSA-3422-45qx-4m3x"}],"sources":{"cve":[{"id":"CVE-2015-4199","description":"Race condition in the IPv6-to-IPv4 functionality in Cisco IOS 15.3S in the Performance Routing Engine (PRE) module on UBR devices allows remote attackers to cause a denial of service (NULL pointer free and module crash) by triggering intermittent connectivity with many IPv6 CPE devices, aka Bug ID CSCug47366.","status":"published","published":"2015-06-27T10:00:00Z","modified":"2024-08-06T06:04:02.979Z","updated_at":"2026-11-02T14:35:43.698357Z"}],"euvd":[{"id":"EUVD-2015-4222","description":"Race condition in the IPv6-to-IPv4 functionality in Cisco IOS 15.3S in the Performance Routing Engine (PRE) module on UBR devices allows remote attackers to cause a denial of service (NULL pointer free and module crash) by triggering intermittent connectivity with many IPv6 CPE devices, aka Bug ID CSCug47366.","status":"published","published":"2015-06-27T10:00:00Z","modified":"2024-08-06T06:04:02Z","updated_at":"2026-11-03T02:22:05.081899Z"}],"ghsa":[{"id":"GHSA-3422-45qx-4m3x","title":"Race condition in the IPv6-to-IPv4 functionality in Cisco IOS 15.3S in the Performance Routing...","description":"Race condition in the IPv6-to-IPv4 functionality in Cisco IOS 15.3S in the Performance Routing Engine (PRE) module on UBR devices allows remote attackers to cause a denial of service (NULL pointer free and module crash) by triggering intermittent connectivity with many IPv6 CPE devices, aka Bug ID CSCug47366.","status":"published","published":"2022-05-17T03:13:42Z","modified":"2023-01-27T05:07:18Z","cwes":["CWE-362"],"updated_at":"2026-11-02T14:43:05.912007Z"}],"nvd":[{"id":"CVE-2015-4199","description":"Race condition in the IPv6-to-IPv4 functionality in Cisco IOS 15.3S in the Performance Routing Engine (PRE) module on UBR devices allows remote attackers to cause a denial of service (NULL pointer free and module crash) by triggering intermittent connectivity with many IPv6 CPE devices, aka Bug ID CSCug47366.","status":"published","published":"2015-06-27T10:59:00.143Z","modified":"2026-06-17T00:26:54.403Z","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-362"],"updated_at":"2026-11-02T14:03:05.884985Z"}]}}