CVE-2018-18397
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,…
Does this matter?
Lower severity and a low EPSS score (0.51%). Track it; it rarely justifies an emergency change on its own.
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.
- CVSS 3.0
- 5.5 MEDIUMCVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
- EPSS
- 0.51% probability · 43th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- 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
- Source
- cve@mitre.org
EPSS 0.5% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=29ec90660d68bbdd69507c1c8b4e33aa299278b1Patch, Third Party Advisory
- https://access.redhat.com/errata/RHBA-2019:0327Third Party Advisory
- https://access.redhat.com/errata/RHSA-2019:0163Third Party Advisory
- https://access.redhat.com/errata/RHSA-2019:0202Third Party Advisory
- https://access.redhat.com/errata/RHSA-2019:0324Third Party Advisory
- https://access.redhat.com/errata/RHSA-2019:0831Third Party Advisory
- https://bugs.chromium.org/p/project-zero/issues/detail?id=1700Exploit, Issue Tracking, Third Party Advisory
- https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.14.87Patch, Vendor Advisory
- https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.19.7Patch, Vendor Advisory
- https://github.com/torvalds/linux/commit/29ec90660d68bbdd69507c1c8b4e33aa299278b1Patch, Third Party Advisory
- https://usn.ubuntu.com/3901-1/Third Party Advisory
- https://usn.ubuntu.com/3901-2/Third Party Advisory
- https://usn.ubuntu.com/3903-1/Third Party Advisory
- https://usn.ubuntu.com/3903-2/Third Party Advisory
- http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=29ec90660d68bbdd69507c1c8b4e33aa299278b1Patch, Third Party Advisory
- https://access.redhat.com/errata/RHBA-2019:0327Third Party Advisory
- https://access.redhat.com/errata/RHSA-2019:0163Third Party Advisory
- https://access.redhat.com/errata/RHSA-2019:0202Third Party Advisory
- https://access.redhat.com/errata/RHSA-2019:0324Third Party Advisory
- https://access.redhat.com/errata/RHSA-2019:0831Third Party Advisory
- https://bugs.chromium.org/p/project-zero/issues/detail?id=1700Exploit, Issue Tracking, Third Party Advisory
- https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.14.87Patch, Vendor Advisory
- https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.19.7Patch, Vendor Advisory
- https://github.com/torvalds/linux/commit/29ec90660d68bbdd69507c1c8b4e33aa299278b1Patch, Third Party Advisory
- https://usn.ubuntu.com/3901-1/Third Party Advisory
- https://usn.ubuntu.com/3901-2/Third Party Advisory
- https://usn.ubuntu.com/3903-1/Third Party Advisory
- https://usn.ubuntu.com/3903-2/Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.