{"id":"CVE-2018-18397","url":"https://www.cyber-defence.io/tools/cve/CVE-2018-18397","generatedAt":"2026-10-29T03:02:22.151Z","title":"The userfaultfd implementation in the Linux kernel before 4.19.7 mishandles access control for certain UFFDIO_ ioctl calls, as demonstrated by allowing local users to write data into holes in a tmpfs file (if the user has read-only access to that file,…","description":"The userfaultfd implementation in the Linux kernel before 4.19.7 mishandles access control for certain UFFDIO_ ioctl calls, as demonstrated by allowing local users to write data into holes in a tmpfs file (if the user has read-only access to that file, and that file contains holes), related to fs/userfaultfd.c and mm/userfaultfd.c.","published":"2018-12-12T10:29:00.000Z","lastModified":"2026-06-17T01:47:09.000Z","status":"Modified","sourceIdentifier":"cve@mitre.org","cvss":{"version":"3.0","score":5.5,"severity":"MEDIUM","vector":"CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N"},"cwe":["CWE-863"],"affected":["linux/linux kernel","redhat/openshift container platform","redhat/virtualization host","redhat/enterprise linux desktop","redhat/enterprise linux server","redhat/enterprise linux server aus","redhat/enterprise linux server eus","redhat/enterprise linux server tus","redhat/enterprise linux workstation","canonical/ubuntu linux"],"epss":{"score":0.0051,"percentile":0.43314,"date":"2026-10-27","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 (0.51%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=29ec90660d68bbdd69507c1c8b4e33aa299278b1","tags":["Patch","Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://access.redhat.com/errata/RHBA-2019:0327","tags":["Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://access.redhat.com/errata/RHSA-2019:0163","tags":["Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://access.redhat.com/errata/RHSA-2019:0202","tags":["Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://access.redhat.com/errata/RHSA-2019:0324","tags":["Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://access.redhat.com/errata/RHSA-2019:0831","tags":["Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://bugs.chromium.org/p/project-zero/issues/detail?id=1700","tags":["Exploit","Issue Tracking","Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.14.87","tags":["Patch","Vendor Advisory"],"source":"cve@mitre.org"},{"url":"https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.19.7","tags":["Patch","Vendor Advisory"],"source":"cve@mitre.org"},{"url":"https://github.com/torvalds/linux/commit/29ec90660d68bbdd69507c1c8b4e33aa299278b1","tags":["Patch","Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://usn.ubuntu.com/3901-1/","tags":["Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://usn.ubuntu.com/3901-2/","tags":["Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://usn.ubuntu.com/3903-1/","tags":["Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://usn.ubuntu.com/3903-2/","tags":["Third Party Advisory"],"source":"cve@mitre.org"},{"url":"http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=29ec90660d68bbdd69507c1c8b4e33aa299278b1","tags":["Patch","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://access.redhat.com/errata/RHBA-2019:0327","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://access.redhat.com/errata/RHSA-2019:0163","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://access.redhat.com/errata/RHSA-2019:0202","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://access.redhat.com/errata/RHSA-2019:0324","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://access.redhat.com/errata/RHSA-2019:0831","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://bugs.chromium.org/p/project-zero/issues/detail?id=1700","tags":["Exploit","Issue Tracking","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.14.87","tags":["Patch","Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.19.7","tags":["Patch","Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://github.com/torvalds/linux/commit/29ec90660d68bbdd69507c1c8b4e33aa299278b1","tags":["Patch","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://usn.ubuntu.com/3901-1/","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://usn.ubuntu.com/3901-2/","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://usn.ubuntu.com/3903-1/","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://usn.ubuntu.com/3903-2/","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2018-18397","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."}