{"cve":"CVE-2021-20257","nvd":{"published":"2022-03-16T15:15:09.983","modified":"2026-06-17T03:33:33.443","status":"Modified","description":"An infinite loop flaw was found in the e1000 NIC emulator of the QEMU. This issue occurs while processing transmits (tx) descriptors in process_tx_desc if various descriptor fields are initialized with invalid values. This flaw allows a guest to consume CPU cycles on the host, resulting in a denial of service. The highest threat from this vulnerability is to system availability.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H","score":6.5},"cwes":["CWE-835"],"references":["https://bugzilla.redhat.com/show_bug.cgi?id=1930087","https://github.com/qemu/qemu/commit/3de46e6fc489c52c9431a8a832ad8170a7569bd8","https://lists.debian.org/debian-lts-announce/2022/09/msg00008.html","https://lists.gnu.org/archive/html/qemu-devel/2021-02/msg07428.html","https://security.gentoo.org/glsa/202208-27"],"products":["debian:debian_linux","fedoraproject:fedora","qemu:qemu","redhat:codeready_linux_builder","redhat:enterprise_linux","redhat:enterprise_linux_for_ibm_z_systems","redhat:enterprise_linux_for_power_little_endian","redhat:openstack_platform"],"source":"nvd","synced_at":"2026-10-19T21:29:06.454770966+00:00"},"epss":{"cve":"CVE-2021-20257","score":0.0037,"percentile":0.30894,"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."]}