{"cve":"CVE-2021-3748","nvd":{"published":"2022-03-23T20:15:09.893","modified":"2026-06-17T04:05:41.413","status":"Modified","description":"A use-after-free vulnerability was found in the virtio-net device of QEMU. It could occur when the descriptor's address belongs to the non direct access region, due to num_buffers being set after the virtqueue elem has been unmapped. A malicious guest could use this flaw to crash QEMU, resulting in a denial of service condition, or potentially execute code on the host with the privileges of the QEMU process.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H","score":7.5},"cwes":["CWE-416"],"references":["https://bugzilla.redhat.com/show_bug.cgi?id=1998514","https://github.com/qemu/qemu/commit/bedd7e93d01961fcb16a97ae45d93acf357e11f6","https://lists.debian.org/debian-lts-announce/2022/04/msg00002.html","https://lists.debian.org/debian-lts-announce/2022/09/msg00008.html","https://lists.nongnu.org/archive/html/qemu-devel/2021-09/msg00388.html"],"products":["canonical:ubuntu_linux","debian:debian_linux","fedoraproject:fedora","qemu:qemu","redhat:enterprise_linux","redhat:enterprise_linux_advanced_virtualization_eus"],"source":"nvd","synced_at":"2026-10-19T21:29:06.454770966+00:00"},"epss":{"cve":"CVE-2021-3748","score":0.00522,"percentile":0.44301,"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."]}