{"schema_version":"1","data":[{"id":24283,"advisory_id":"95e878f9-7243-4ba1-bb37-9b2ad4355b73","revision":1,"source_id":"core-cve","source_url":"https://www.cve.org/CVERecord?id=CVE-2023-4921","source_published_at":"2023-09-12T19:45:19.367+00:00","published_at":"2026-10-25T06:33:01.116305+00:00","extraction_method":"structured","technologies":["core-cve","kernel"],"cve_ids":["CVE-2023-4921"],"event_types":["advisory"],"payload":{"kind":"advisory","title":"Use-after-free in Linux kernel's net/sched: sch_qfq component","summary":"A use-after-free vulnerability in the Linux kernel's net/sched: sch_qfq component can be exploited to achieve local privilege escalation. When 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(). We recommend upgrading past commit 8fc134fee27f2263988ae38920bc03da416b03d8.","evidence":"cve:CVE-2023-4921","products":[{"name":{"value":"Kernel","evidence":"/containers/cna/affected/0/product"},"prerequisites":[],"fixed_versions":[],"affected_versions":[]}],"severity":"high","structured":{"id":"CVE-2023-4921","aliases":["CVE-2023-4921"],"metrics":[{"format":"CVSS","cvssV3_1":{"scope":"UNCHANGED","version":"3.1","baseScore":7.8,"attackVector":"LOCAL","baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","integrityImpact":"HIGH","userInteraction":"NONE","attackComplexity":"LOW","availabilityImpact":"HIGH","privilegesRequired":"LOW","confidentialityImpact":"HIGH"},"scenarios":[{"lang":"en","value":"GENERAL"}]}],"affected":[{"repo":"https://git.kernel.org","vendor":"Linux","product":"Kernel","versions":[{"status":"affected","version":"3.8","lessThan":"6.6","versionType":"custom"}],"packageName":"kernel","defaultStatus":"unaffected"}],"modified":"2026-10-14T21:49:38.794Z","provider":"cve","references":["https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=8fc134fee27f2263988ae38920bc03da416b03d8","https://kernel.dance/8fc134fee27f2263988ae38920bc03da416b03d8","https://lists.debian.org/debian-lts-announce/2023/10/msg00027.html","https://lists.debian.org/debian-lts-announce/2024/01/msg00004.html"],"provider_metadata":{"adp":[{"title":"CVE Program Container","references":[{"url":"https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=8fc134fee27f2263988ae38920bc03da416b03d8","tags":["patch","x_transferred"]},{"url":"https://kernel.dance/8fc134fee27f2263988ae38920bc03da416b03d8","tags":["x_transferred"]},{"url":"https://lists.debian.org/debian-lts-announce/2023/10/msg00027.html","tags":["x_transferred"]},{"url":"https://lists.debian.org/debian-lts-announce/2024/01/msg00004.html","tags":["x_transferred"]}],"providerMetadata":{"orgId":"af854a3a-2127-422b-91ae-364da2661108","shortName":"CVE","dateUpdated":"2024-08-02T07:44:52.210Z"}},{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2023-4921","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2024-05-10T04:00:09.695048Z"}}}],"providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-02-25T17:20:09.498Z"}},{"affected":[{"vendor":"Siemens","product":"SIMATIC S7-1500 CPU 1518-4 PN/DP MFP","versions":[{"status":"affected","version":"V3.1.0","lessThan":"V3.1.5","versionType":"custom"}],"defaultStatus":"unknown"},{"vendor":"Siemens","product":"SIMATIC S7-1500 CPU 1518-4 PN/DP MFP","versions":[{"status":"affected","version":"V3.1.0","lessThan":"V3.1.5","versionType":"custom"}],"defaultStatus":"unknown"},{"vendor":"Siemens","product":"SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP","versions":[{"status":"affected","version":"V3.1.0","lessThan":"V3.1.5","versionType":"custom"}],"defaultStatus":"unknown"},{"vendor":"Siemens","product":"SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP","versions":[{"status":"affected","version":"V3.1.0","lessThan":"V3.1.5","versionType":"custom"}],"defaultStatus":"unknown"},{"vendor":"Siemens","product":"SIMATIC S7-1500 TM MFP - GNU/Linux subsystem","versions":[{"status":"affected","version":"0","lessThan":"V1.1","versionType":"custom"}],"defaultStatus":"unknown"},{"vendor":"Siemens","product":"SIPLUS S7-1500 CPU 1518-4 PN/DP MFP","versions":[{"status":"affected","version":"V3.1.0","lessThan":"V3.1.5","versionType":"custom"}],"defaultStatus":"unknown"}],"x_adpType":"supplier","references":[{"url":"https://cert-portal.siemens.com/productcert/html/ssa-794697.html"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-398330.html"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-769027.html"}],"providerMetadata":{"orgId":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e","shortName":"siemens-SADP","dateUpdated":"2026-10-14T21:49:38.794Z"}}],"cna":{"orgId":"14ed7db2-1595-443d-9d34-6215bf890778","shortName":"Google","dateUpdated":"2024-01-11T19:06:28.103Z"}}},"related_cves":[{"value":"CVE-2023-4921","evidence":"/cveMetadata/cveId"}],"security_relevant":true,"severity_evidence":"/containers/cna/metrics"}}],"next_after":24283,"next_before":24283}