{"id":"CVE-2021-33656","title":"When setting font with malicous data by ioctl cmd PIO_FONT,kernel will write memory out of bounds.","summary":"When setting font with malicous data by ioctl cmd PIO_FONT,kernel will write memory out of bounds.","severity":"medium","cvss":6.8,"cvssVector":"CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","cwe":["CWE-787","CWE-787"],"vendor":"openatom","product":"openeuler","affected":["openeuler = 20.03","linux_kernel < 5.10.127","debian_linux = 10.0"],"patched":["linux_kernel 5.10.127"],"published":"2022-07-18","updated":"2026-10-08","sourceUpdated":"2026-10-08T22:17:10.127","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2021-33656","references":[{"url":"http://www.openwall.com/lists/oss-security/2022/07/19/3","label":"securities@openeuler.org"},{"url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git/tree/releases/5.10.127/vt-drop-old-font-ioctls.patch","label":"securities@openeuler.org"},{"url":"https://lists.debian.org/debian-lts-announce/2022/10/msg00000.html","label":"securities@openeuler.org"},{"url":"https://www.openeuler.org/en/security/cve/detail.html?id=CVE-2021-33656&packageName=kernel","label":"securities@openeuler.org"},{"url":"http://www.openwall.com/lists/oss-security/2022/07/19/3","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git/tree/releases/5.10.127/vt-drop-old-font-ioctls.patch","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.debian.org/debian-lts-announce/2022/10/msg00000.html","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.openeuler.org/en/security/cve/detail.html?id=CVE-2021-33656&packageName=kernel","label":"af854a3a-2127-422b-91ae-364da2661108"}],"tags":["nvd"],"epss":0.00611,"epssPercentile":0.47668,"ingestedAt":"2026-10-08T23:16:47.346Z","slug":"CVE-2021-33656","body":"## Overview\n\nWhen setting font with malicous data by ioctl cmd PIO_FONT,kernel will write memory out of bounds.\n\n## Affected\n\n- `openeuler = 20.03`\n- `linux_kernel < 5.10.127`\n- `debian_linux = 10.0`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `linux_kernel 5.10.127`","depth":"sunlit","depthScore":38,"depthScoreParts":{"impact":37.4,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}