{"schemaVersion":3,"id":"CVE-2021-38598","aliases":["GHSA-hvm4-mc7m-22w4","PYSEC-2021-360","UBUNTU-CVE-2021-38598","DEBIAN-CVE-2021-38598"],"status":"published","duplicateOf":null,"title":null,"description":"OpenStack Neutron before 16.4.1, 17.x before 17.1.3, and 18.0.0 allows hardware address impersonation when the linuxbridge driver with ebtables-nft is used on a Netfilter-based platform. By sending carefully crafted packets, anyone in control of a server instance connected to the virtual switch can impersonate the hardware addresses of other systems on the network, resulting in denial of service or in some cases possibly interception of traffic intended for other destinations.","dates":{"published":"2021-08-23T04:17:16.000Z","modified":"2024-08-04T01:44:23.505Z","reserved":null,"kevAdded":[],"kevDue":[]},"cvss":{"headline":{"score":9.1,"severity":"critical","version":"3.1","versionLabel":"v3.1","source":"NVD","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H","computed":false,"selection":"backend-summary"},"metrics":[{"version":"4.0","versionLabel":"v4.0","source":"OSV · Pypi","score":8.8,"severity":"high","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N","exploitability":null,"impact":null,"computed":true},{"version":"3.1","versionLabel":"v3.1","source":"OSV · Pypi","score":9.1,"severity":"critical","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H","exploitability":10,"impact":8.7,"computed":true},{"version":"3.1","versionLabel":"v3.1","source":"OSV · Ubuntu","score":9.1,"severity":"critical","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H","exploitability":10,"impact":8.7,"computed":true},{"version":"3.1","versionLabel":"v3.1","source":"OSV · Debian","score":9.1,"severity":"critical","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H","exploitability":10,"impact":8.7,"computed":true},{"version":"3.1","versionLabel":"v3.1","source":"NVD","score":9.1,"severity":"critical","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H","exploitability":null,"impact":null,"computed":false},{"version":"2.0","versionLabel":"v2.0","source":"NVD","score":5.8,"severity":"medium","vector":"AV:N/AC:M/Au:N/C:N/I:P/A:P","exploitability":null,"impact":null,"computed":false}]},"epss":{"probability":0.0122,"percentile":0.68247,"severity":"low","asOf":"2026-10-19T00:00:00.000Z","change":{"pp":0,"baselineDate":"2026-09-19T00:00:00.000Z","baselineScore":0.0122},"history":[{"date":"2026-09-14T00:00:00.000Z","score":0.0122,"percentile":null},{"date":"2026-09-15T00:00:00.000Z","score":0.0122,"percentile":null},{"date":"2026-09-16T00:00:00.000Z","score":0.0122,"percentile":null},{"date":"2026-09-17T00:00:00.000Z","score":0.0122,"percentile":null},{"date":"2026-09-18T00:00:00.000Z","score":0.0122,"percentile":null},{"date":"2026-09-19T00:00:00.000Z","score":0.0122,"percentile":null},{"date":"2026-09-20T00:00:00.000Z","score":0.0122,"percentile":null},{"date":"2026-09-21T00:00:00.000Z","score":0.0122,"percentile":null},{"date":"2026-09-22T00:00:00.000Z","score":0.0122,"percentile":null},{"date":"2026-09-23T00:00:00.000Z","score":0.0122,"percentile":null},{"date":"2026-09-24T00:00:00.000Z","score":0.0122,"percentile":null},{"date":"2026-09-25T00:00:00.000Z","score":0.0122,"percentile":null},{"date":"2026-09-26T00:00:00.000Z","score":0.0122,"percentile":null},{"date":"2026-09-27T00:00:00.000Z","score":0.0122,"percentile":null},{"date":"2026-09-28T00:00:00.000Z","score":0.0122,"percentile":null},{"date":"2026-09-29T00:00:00.000Z","score":0.0122,"percentile":null},{"date":"2026-09-30T00:00:00.000Z","score":0.0122,"percentile":null},{"date":"2026-10-01T00:00:00.000Z","score":0.0122,"percentile":null},{"date":"2026-10-02T00:00:00.000Z","score":0.0122,"percentile":null},{"date":"2026-10-03T00:00:00.000Z","score":0.0122,"percentile":null},{"date":"2026-10-04T00:00:00.000Z","score":0.0122,"percentile":null},{"date":"2026-10-05T00:00:00.000Z","score":0.0122,"percentile":null},{"date":"2026-10-06T00:00:00.000Z","score":0.0122,"percentile":null},{"date":"2026-10-07T00:00:00.000Z","score":0.0122,"percentile":null},{"date":"2026-10-08T00:00:00.000Z","score":0.0122,"percentile":null},{"date":"2026-10-09T00:00:00.000Z","score":0.0122,"percentile":null},{"date":"2026-10-10T00:00:00.000Z","score":0.0122,"percentile":null},{"date":"2026-10-11T00:00:00.000Z","score":0.0122,"percentile":null},{"date":"2026-10-12T00:00:00.000Z","score":0.0122,"percentile":null},{"date":"2026-10-13T00:00:00.000Z","score":0.0122,"percentile":null},{"date":"2026-10-14T00:00:00.000Z","score":0.0122,"percentile":null},{"date":"2026-10-15T00:00:00.000Z","score":0.0122,"percentile":null},{"date":"2026-10-16T00:00:00.000Z","score":0.0122,"percentile":null},{"date":"2026-10-17T00:00:00.000Z","score":0.0122,"percentile":null},{"date":"2026-10-18T00:00:00.000Z","score":0.0122,"percentile":null},{"date":"2026-10-19T00:00:00.000Z","score":0.0122,"percentile":0.68247}],"last30":[{"date":"2026-09-19T00:00:00.000Z","score":0.0122,"percentile":null},{"date":"2026-09-20T00:00:00.000Z","score":0.0122,"percentile":null},{"date":"2026-09-21T00:00:00.000Z","score":0.0122,"percentile":null},{"date":"2026-09-22T00:00:00.000Z","score":0.0122,"percentile":null},{"date":"2026-09-23T00:00:00.000Z","score":0.0122,"percentile":null},{"date":"2026-09-24T00:00:00.000Z","score":0.0122,"percentile":null},{"date":"2026-09-25T00:00:00.000Z","score":0.0122,"percentile":null},{"date":"2026-09-26T00:00:00.000Z","score":0.0122,"percentile":null},{"date":"2026-09-27T00:00:00.000Z","score":0.0122,"percentile":null},{"date":"2026-09-28T00:00:00.000Z","score":0.0122,"percentile":null},{"date":"2026-09-29T00:00:00.000Z","score":0.0122,"percentile":null},{"date":"2026-09-30T00:00:00.000Z","score":0.0122,"percentile":null},{"date":"2026-10-01T00:00:00.000Z","score":0.0122,"percentile":null},{"date":"2026-10-02T00:00:00.000Z","score":0.0122,"percentile":null},{"date":"2026-10-03T00:00:00.000Z","score":0.0122,"percentile":null},{"date":"2026-10-04T00:00:00.000Z","score":0.0122,"percentile":null},{"date":"2026-10-05T00:00:00.000Z","score":0.0122,"percentile":null},{"date":"2026-10-06T00:00:00.000Z","score":0.0122,"percentile":null},{"date":"2026-10-07T00:00:00.000Z","score":0.0122,"percentile":null},{"date":"2026-10-08T00:00:00.000Z","score":0.0122,"percentile":null},{"date":"2026-10-09T00:00:00.000Z","score":0.0122,"percentile":null},{"date":"2026-10-10T00:00:00.000Z","score":0.0122,"percentile":null},{"date":"2026-10-11T00:00:00.000Z","score":0.0122,"percentile":null},{"date":"2026-10-12T00:00:00.000Z","score":0.0122,"percentile":null},{"date":"2026-10-13T00:00:00.000Z","score":0.0122,"percentile":null},{"date":"2026-10-14T00:00:00.000Z","score":0.0122,"percentile":null},{"date":"2026-10-15T00:00:00.000Z","score":0.0122,"percentile":null},{"date":"2026-10-16T00:00:00.000Z","score":0.0122,"percentile":null},{"date":"2026-10-17T00:00:00.000Z","score":0.0122,"percentile":null},{"date":"2026-10-18T00:00:00.000Z","score":0.0122,"percentile":null},{"date":"2026-10-19T00:00:00.000Z","score":0.0122,"percentile":0.68247}]},"kev":{"state":"not-listed","entries":[],"listedCount":0,"totalCatalogs":3,"catalogs":[{"source":"cisa","label":"CISA","listed":false,"entry":null},{"source":"enisa","label":"ENISA","listed":false,"entry":null},{"source":"circl","label":"CIRCL","listed":false,"entry":null}]},"ransomware":{"state":"none-recorded","sources":[]},"exploits":[{"id":"REF_5BC351A093A5F860","name":"Exploit Reference (launchpad.net)","source":"reference","url":"https://launchpad.net/bugs/1938670","maturity":"unknown","reliabilityScore":0.2,"verified":false,"type":null,"platforms":[],"requiresAuth":null,"exploitdb":null,"metasploit":null}],"exploitCount":1,"weaknesses":[{"id":"CWE-290","name":"Authentication Bypass by Spoofing","description":"This attack-focused weakness is caused by incorrectly implemented authentication schemes that are subject to spoofing attacks.","type":"weakness","status":"Incomplete","abstraction":"Base","likelihoodOfExploit":null,"url":"https://cwe.mitre.org/data/definitions/290.html"}],"affected":[{"vendor":"debian","product":"neutron","name":"neutron","label":"neutron","ecosystem":"Debian","cpePart":null,"purl":"pkg:deb/debian/neutron","purlType":"deb","versions":[{"text":"< 2:18.1.0-2","noFixRecorded":false,"fixedIn":null}],"versionsText":"< 2:18.1.0-2","eol":null,"hubHref":null},{"vendor":"ubuntu","product":"neutron","name":"neutron","label":"neutron","ecosystem":"Ubuntu","cpePart":null,"purl":"pkg:deb/ubuntu/neutron","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null},{"text":"< 2:12.1.1-0ubuntu8.1","noFixRecorded":false,"fixedIn":null},{"text":"< 2:16.4.2-0ubuntu6.2","noFixRecorded":false,"fixedIn":null}],"versionsText":"All versions (No fix recorded) | < 2:12.1.1-0ubuntu8.1 | < 2:16.4.2-0ubuntu6.2","eol":null,"hubHref":null},{"vendor":"openstack","product":"neutron","name":"neutron","label":"neutron","ecosystem":null,"cpePart":"a","purl":null,"purlType":null,"versions":[{"text":"< 16.4.1","noFixRecorded":false,"fixedIn":null},{"text":"≥ 17.0.0, < 17.1.3","noFixRecorded":false,"fixedIn":null},{"text":"18.0.0","noFixRecorded":false,"fixedIn":null}],"versionsText":"< 16.4.1 | ≥ 17.0.0, < 17.1.3 | 18.0.0","eol":null,"hubHref":"/vendor/openstack/neutron"},{"vendor":"PyPI","product":"neutron","name":"neutron","label":"neutron","ecosystem":"PyPI","cpePart":null,"purl":"pkg:pypi/neutron","purlType":"pypi","versions":[{"text":"< 16.4.1","noFixRecorded":false,"fixedIn":null},{"text":"≥ 17.0.0, < 17.1.3","noFixRecorded":false,"fixedIn":null},{"text":"18.0.0","noFixRecorded":false,"fixedIn":null},{"text":"≥ 18.0.0, < 18.1.0","noFixRecorded":false,"fixedIn":null}],"versionsText":"< 16.4.1 | ≥ 17.0.0, < 17.1.3 | 18.0.0 | ≥ 18.0.0, < 18.1.0","eol":null,"hubHref":null}],"affectedCount":4,"eol":{"hasEol":false,"count":0},"references":[{"url":"https://launchpad.net/bugs/1938670","label":"launchpad.net/bugs/1938670","hostname":"launchpad.net","tags":["X Refsource MISC","WEB","Exploit","Issue Tracking","Third Party Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-38598","label":"nvd.nist.gov/vuln/detail/CVE-2021-38598","hostname":"nvd.nist.gov","tags":["Advisory"]},{"url":"https://github.com/openstack/neutron/commit/0a931391d8990f3e654b4bfda24ae4119c609bbf","label":"github.com/openstack/neutron/commit/0a931391d8990f3e654b4bfda24ae4119c609bbf","hostname":"github.com","tags":["WEB"]},{"url":"https://github.com/openstack/neutron/commit/cc0d28a3e2ccfad6fc2ff24d78f009cbe3992575","label":"github.com/openstack/neutron/commit/cc0d28a3e2ccfad6fc2ff24d78f009cbe3992575","hostname":"github.com","tags":["WEB"]},{"url":"https://github.com/openstack/neutron","label":"github.com/openstack/neutron","hostname":"github.com","tags":["PACKAGE"]},{"url":"https://github.com/pypa/advisory-database/tree/main/vulns/neutron/PYSEC-2021-360.yaml","label":"github.com/pypa/advisory-database/tree/main/vulns/neutron/PYSEC-2021-360.yaml","hostname":"github.com","tags":["WEB"]},{"url":"https://opendev.org/openstack/neutron/commit/fafa5dacd5057120562184a734e7345e7c0e9639","label":"opendev.org/openstack/neutron/commit/fafa5dacd5057120562184a734e7345e7c0e9639","hostname":"opendev.org","tags":["WEB"]},{"url":"https://github.com/advisories/GHSA-hvm4-mc7m-22w4","label":"github.com/advisories/GHSA-hvm4-mc7m-22w4","hostname":"github.com","tags":["Advisory"]},{"url":"https://ubuntu.com/security/CVE-2021-38598","label":"ubuntu.com/security/CVE-2021-38598","hostname":"ubuntu.com","tags":["REPORT"]},{"url":"https://www.openwall.com/lists/oss-security/2021/08/17/4","label":"www.openwall.com/lists/oss-security/2021/08/17/4","hostname":"www.openwall.com","tags":["REPORT"]},{"url":"https://review.opendev.org/c/openstack/neutron/+/785917/","label":"review.opendev.org/c/openstack/neutron/+/785917/","hostname":"review.opendev.org","tags":["REPORT"]},{"url":"https://ubuntu.com/security/notices/USN-6067-1","label":"ubuntu.com/security/notices/USN-6067-1","hostname":"ubuntu.com","tags":["Advisory"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2021-38598","label":"www.cve.org/CVERecord?id=CVE-2021-38598","hostname":"www.cve.org","tags":["REPORT"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2021-38598","label":"security-tracker.debian.org/tracker/CVE-2021-38598","hostname":"security-tracker.debian.org","tags":["Advisory"]}],"lineage":{"upstream":[],"downstream":["USN-6067-1"],"duplicates":[],"related":["USN-6067-1"]},"timeline":[{"kind":"published","date":"2021-08-23T04:17:16.000Z","label":"Published","detail":"Vulnerability first disclosed.","source":null},{"kind":"modified","date":"2024-08-04T01:44:23.505Z","label":"Last modified","detail":"Vulnerability information updated.","source":null}],"risk":{"score":70,"level":"high","profile":"Default","thresholds":{"critical":75,"high":50,"medium":25,"low":10}},"meta":{"dataAsOf":"2026-10-19T16:42:36.849Z","stale":false,"partial":false}}