{"cve":"CVE-2023-4208","nvd":{"published":"2023-09-06T14:15:11.627","modified":"2026-06-17T06:37:19.093","status":"Modified","description":"A use-after-free vulnerability in the Linux kernel's net/sched: cls_u32 component can be exploited to achieve local privilege escalation.\n\nWhen u32_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 3044b16e7c6fe5d24b1cdbcf1bd0a9d92d1ebd81.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8},"cwes":["CWE-416"],"references":["https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=3044b16e7c6fe5d24b1cdbcf1bd0a9d92d1ebd81","https://kernel.dance/3044b16e7c6fe5d24b1cdbcf1bd0a9d92d1ebd81","https://lists.debian.org/debian-lts-announce/2024/01/msg00004.html","https://www.debian.org/security/2023/dsa-5492","https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=3044b16e7c6fe5d24b1cdbcf1bd0a9d92d1ebd81"],"products":["debian:debian_linux","linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:39:24.235896374+00:00"},"epss":{"cve":"CVE-2023-4208","score":0.00312,"percentile":0.24133,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}