{"id":"CVE-2023-4207","url":"https://www.cyber-defence.io/tools/cve/CVE-2023-4207","generatedAt":"2026-10-28T02:16:56.822Z","title":"A use-after-free vulnerability in the Linux kernel's net/sched: cls_fw component can be exploited to achieve local privilege escalation.","description":"A use-after-free vulnerability in the Linux kernel's net/sched: cls_fw component can be exploited to achieve local privilege escalation.\n\nWhen fw_change() is called on an existing filter, the whole tcf_result struct is always copied into the new instance of the filter. This causes a problem when updating a filter bound to a class, as tcf_unbind_filter() is always called on the old instance in the success path, decreasing filter_cnt of the still referenced class and allowing it to be deleted, leading to a use-after-free.\n\nWe recommend upgrading past commit 76e42ae831991c828cffa8c37736ebfb831ad5ec.","published":"2023-09-06T14:15:11.000Z","lastModified":"2026-06-17T06:37:19.000Z","status":"Modified","sourceIdentifier":"cve-coordination@google.com","cvss":{"version":"3.1","score":7.8,"severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"},"cwe":["CWE-416"],"affected":["linux/linux kernel","debian/debian linux"],"epss":{"score":0.00316,"percentile":0.24309,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.32%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=76e42ae831991c828cffa8c37736ebfb831ad5ec","tags":["Issue Tracking","Mailing List","Patch","Vendor Advisory"],"source":"cve-coordination@google.com"},{"url":"https://kernel.dance/76e42ae831991c828cffa8c37736ebfb831ad5ec","tags":["Patch","Vendor Advisory"],"source":"cve-coordination@google.com"},{"url":"https://lists.debian.org/debian-lts-announce/2024/01/msg00004.html","tags":["Mailing List","Third Party Advisory","VDB Entry"],"source":"cve-coordination@google.com"},{"url":"https://www.debian.org/security/2023/dsa-5492","tags":["Third Party Advisory"],"source":"cve-coordination@google.com"},{"url":"https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=76e42ae831991c828cffa8c37736ebfb831ad5ec","tags":["Issue Tracking","Mailing List","Patch","Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://kernel.dance/76e42ae831991c828cffa8c37736ebfb831ad5ec","tags":["Patch","Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.debian.org/debian-lts-announce/2024/01/msg00004.html","tags":["Mailing List","Third Party Advisory","VDB Entry"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.debian.org/security/2023/dsa-5492","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2023-4207","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}