{"id":"CVE-2021-23270","aliases":["EUVD-2021-10365","GHSA-wqw9-vmhv-jg2w"],"status":"published","title":"In Gargoyle OS 1.12.0, when IPv6 is used, a routing loop can occur that generates excessive...","description":"In Gargoyle OS 1.12.0, when IPv6 is used, a routing loop can occur that generates excessive network traffic between an affected device and its upstream ISP's router. This occurs when a link prefix route points to a point-to-point link, a destination IPv6 address belongs to the prefix and is not a local IPv6 address, and a router advertisement is received with at least one global unique IPv6 prefix for which the on-link flag is set.","severity":{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-12","score":0.01034,"percentile":0.64315,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-834"],"published":"2021-04-12T17:40:59Z","modified":"2026-10-20T10:54:32Z","products":[{"vendor":"gargoyle-router","product":"gargoyle"}],"references":[{"url":"https://github.com/ericpaulbishop/gargoyle/commit/24afe944a6ffff53d84a748384e276a4e95912ec","tags":["x_refsource_MISC","x_transferred","Patch","Third Party Advisory","fix"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-23270"},{"url":"https://github.com/advisories/GHSA-wqw9-vmhv-jg2w"}],"sources":{"cve":[{"id":"CVE-2021-23270","description":"In Gargoyle OS 1.12.0, when IPv6 is used, a routing loop can occur that generates excessive network traffic between an affected device and its upstream ISP's router. This occurs when a link prefix route points to a point-to-point link, a destination IPv6 address belongs to the prefix and is not a local IPv6 address, and a router advertisement is received with at least one global unique IPv6 prefix for which the on-link flag is set.","status":"published","published":"2021-04-12T17:40:59Z","modified":"2024-08-03T19:05:55.638Z","updated_at":"2026-11-02T14:33:00.819444Z"}],"euvd":[{"id":"EUVD-2021-10365","description":"In Gargoyle OS 1.12.0, when IPv6 is used, a routing loop can occur that generates excessive network traffic between an affected device and its upstream ISP's router. This occurs when a link prefix route points to a point-to-point link, a destination IPv6 address belongs to the prefix and is not a local IPv6 address, and a router advertisement is received with at least one global unique IPv6 prefix for which the on-link flag is set.","status":"published","published":"2021-04-12T17:40:59Z","modified":"2024-08-03T19:05:55Z","updated_at":"2026-11-03T03:25:00.126172Z"}],"ghsa":[{"id":"GHSA-wqw9-vmhv-jg2w","title":"In Gargoyle OS 1.12.0, when IPv6 is used, a routing loop can occur that generates excessive...","description":"In Gargoyle OS 1.12.0, when IPv6 is used, a routing loop can occur that generates excessive network traffic between an affected device and its upstream ISP's router. This occurs when a link prefix route points to a point-to-point link, a destination IPv6 address belongs to the prefix and is not a local IPv6 address, and a router advertisement is received with at least one global unique IPv6 prefix for which the on-link flag is set.","status":"published","published":"2022-05-24T17:47:07Z","modified":"2023-01-29T05:06:21Z","cwes":["CWE-834"],"updated_at":"2026-11-02T14:46:00.036476Z"}],"nvd":[{"id":"CVE-2021-23270","description":"In Gargoyle OS 1.12.0, when IPv6 is used, a routing loop can occur that generates excessive network traffic between an affected device and its upstream ISP's router. This occurs when a link prefix route points to a point-to-point link, a destination IPv6 address belongs to the prefix and is not a local IPv6 address, and a router advertisement is received with at least one global unique IPv6 prefix for which the on-link flag is set.","status":"published","published":"2021-04-12T19:15:14.517Z","modified":"2026-06-17T03:38:31.193Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"primary"},{"version":"2.0","score":4.3,"vector":"AV:N/AC:M/Au:N/C:N/I:N/A:P","level":"medium","assessor":"primary"}],"cwes":["CWE-834"],"updated_at":"2026-11-02T14:06:51.610648Z"}],"osv":[{"id":"CVE-2021-23270","description":"In Gargoyle OS 1.12.0, when IPv6 is used, a routing loop can occur that generates excessive network traffic between an affected device and its upstream ISP's router. This occurs when a link prefix route points to a point-to-point link, a destination IPv6 address belongs to the prefix and is not a local IPv6 address, and a router advertisement is received with at least one global unique IPv6 prefix for which the on-link flag is set.","status":"published","published":"2021-04-12T19:15:14.517Z","modified":"2026-10-20T10:54:32.583112804Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"updated_at":"2026-11-02T15:44:18.367807Z"}]}}