{"id":"CVE-2021-33624","url":"https://www.cyber-defence.io/tools/cve/CVE-2021-33624","generatedAt":"2026-10-27T23:45:50.625Z","title":"In kernel/bpf/verifier.c in the Linux kernel before 5.12.13, a branch can be mispredicted (e.g., because of type confusion) and consequently an unprivileged BPF program can read arbitrary memory locations via a side-channel attack, aka CID-9183671af6db.","description":"In kernel/bpf/verifier.c in the Linux kernel before 5.12.13, a branch can be mispredicted (e.g., because of type confusion) and consequently an unprivileged BPF program can read arbitrary memory locations via a side-channel attack, aka CID-9183671af6db.","published":"2021-06-23T16:15:08.000Z","lastModified":"2026-10-08T21:17:36.000Z","status":"Modified","sourceIdentifier":"cve@mitre.org","cvss":{"version":"3.1","score":4.7,"severity":"MEDIUM","vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N"},"cwe":["CWE-843"],"affected":["linux/linux kernel","debian/debian linux"],"epss":{"score":0.00922,"percentile":0.60101,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.92%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"http://www.openwall.com/lists/oss-security/2021/06/21/1","tags":["Exploit","Mailing List","Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://github.com/benschlueter/CVE-2021-33624","source":"cve@mitre.org"},{"url":"https://github.com/torvalds/linux/commit/9183671af6dbf60a1219371d4ed73e23f43b49db","tags":["Patch","Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://lists.debian.org/debian-lts-announce/2021/10/msg00010.html","tags":["Issue Tracking","Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://www.usenix.org/conference/usenixsecurity21/presentation/kirzner","tags":["Third Party Advisory"],"source":"cve@mitre.org"},{"url":"http://www.openwall.com/lists/oss-security/2021/06/21/1","tags":["Exploit","Mailing List","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://github.com/torvalds/linux/commit/9183671af6dbf60a1219371d4ed73e23f43b49db","tags":["Patch","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.debian.org/debian-lts-announce/2021/10/msg00010.html","tags":["Issue Tracking","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.usenix.org/conference/usenixsecurity21/presentation/kirzner","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2021-33624","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}