{"id":"AZL-28779","summary":"CVE-2023-4921 affecting package kernel for versions less than 5.15.133.1-1","details":"A use-after-free vulnerability in the Linux kernel's net/sched: sch_qfq component can be exploited to achieve local privilege escalation.\n\nWhen the plug qdisc is used as a class of the qfq qdisc, sending network packets triggers use-after-free in qfq_dequeue() due to the incorrect .peek handler of sch_plug and lack of error checking in agg_dequeue().\n\nWe recommend upgrading past commit 8fc134fee27f2263988ae38920bc03da416b03d8.","modified":"2026-04-21T04:25:59.516211Z","published":"2023-09-12T20:15:10Z","upstream":["CVE-2023-4921"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2023-4921"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:2","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.15.133.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-28779.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"}]}