{"cve":"CVE-2021-20203","nvd":{"published":"2021-02-25T20:15:11.597","modified":"2026-06-17T03:33:27.903","status":"Modified","description":"An integer overflow issue was found in the vmxnet3 NIC emulator of the QEMU for versions up to v5.2.0. It may occur if a guest was to supply invalid values for rx/tx queue size or other NIC parameters. A privileged guest user may use this flaw to crash the QEMU process on the host resulting in DoS scenario.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:N/I:N/A:L","score":3.2},"cwes":["CWE-190"],"references":["https://bugs.launchpad.net/qemu/+bug/1913873","https://bugzilla.redhat.com/show_bug.cgi?id=1922441","https://lists.debian.org/debian-lts-announce/2021/04/msg00009.html","https://lists.debian.org/debian-lts-announce/2022/09/msg00008.html","https://security.gentoo.org/glsa/202208-27"],"products":["debian:debian_linux","fedoraproject:fedora","qemu:qemu"],"source":"nvd","synced_at":"2026-10-19T21:15:50.279857260+00:00"},"epss":{"cve":"CVE-2021-20203","score":0.00592,"percentile":0.48324,"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."]}