{"id":"CVE-2021-3997","title":"A flaw was found in systemd","summary":"A flaw was found in systemd. An uncontrolled recursion in systemd-tmpfiles may lead to a denial of service at boot time when too many nested directories are created in /tmp.","severity":"medium","cvss":5.5,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","cwe":["CWE-674","CWE-674"],"vendor":"systemd_project","product":"systemd","affected":["systemd >= 240, < 250.2","fedora = 34","fedora = 35","enterprise_linux = 7.0","enterprise_linux = 8.0","enterprise_linux = 9.0"],"patched":["systemd 250.2"],"published":"2022-08-23","updated":"2026-10-14","sourceUpdated":"2026-10-14T10:17:49.307","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2021-3997","references":[{"url":"https://access.redhat.com/security/cve/CVE-2021-3997","label":"secalert@redhat.com"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2024639","label":"secalert@redhat.com"},{"url":"https://github.com/systemd/systemd/commit/5b1cf7a9be37e20133c0208005274ce4a5b5c6a1","label":"secalert@redhat.com"},{"url":"https://security.gentoo.org/glsa/202305-15","label":"secalert@redhat.com"},{"url":"https://www.openwall.com/lists/oss-security/2022/01/10/2","label":"secalert@redhat.com"},{"url":"https://access.redhat.com/security/cve/CVE-2021-3997","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2024639","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://github.com/systemd/systemd/commit/5b1cf7a9be37e20133c0208005274ce4a5b5c6a1","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://security.gentoo.org/glsa/202305-15","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.openwall.com/lists/oss-security/2022/01/10/2","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-398330.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"}],"tags":["nvd"],"epss":0.01694,"epssPercentile":0.7653,"ingestedAt":"2026-10-14T10:25:41.193Z","slug":"CVE-2021-3997","body":"## Overview\n\nA flaw was found in systemd. An uncontrolled recursion in systemd-tmpfiles may lead to a denial of service at boot time when too many nested directories are created in /tmp.\n\n## Affected\n\n- `systemd >= 240, < 250.2`\n- `fedora = 34`\n- `fedora = 35`\n- `enterprise_linux = 7.0`\n- `enterprise_linux = 8.0`\n- `enterprise_linux = 9.0`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `systemd 250.2`","depth":"sunlit","depthScore":31,"depthScoreParts":{"impact":30.3,"likelihood":0.3,"exploitation":0,"ransomware":0},"changes":[]}