{"cve":"CVE-2021-20221","nvd":{"published":"2021-05-13T16:15:07.697","modified":"2026-06-17T03:33:29.773","status":"Modified","description":"An out-of-bounds heap buffer access issue was found in the ARM Generic Interrupt Controller emulator of QEMU up to and including qemu 4.2.0on aarch64 platform. The issue occurs because while writing an interrupt ID to the controller memory area, it is not masked to be 4 bits wide. It may lead to the said issue while updating controller state fields and their subsequent processing. 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:H","score":6.0},"cwes":["CWE-125","CWE-787"],"references":["http://www.openwall.com/lists/oss-security/2021/02/05/1","https://bugzilla.redhat.com/show_bug.cgi?id=1924601","https://lists.debian.org/debian-lts-announce/2021/02/msg00024.html","https://lists.debian.org/debian-lts-announce/2022/09/msg00008.html","https://security.netapp.com/advisory/ntap-20210708-0005/"],"products":["debian:debian_linux","qemu:qemu","redhat:enterprise_linux"],"source":"nvd","synced_at":"2026-10-19T21:18:09.669877188+00:00"},"epss":{"cve":"CVE-2021-20221","score":0.00326,"percentile":0.25703,"date":"2026-11-01"},"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."]}