CVE-2018-18397

Public Exploit

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.

Category

5.5
CVSS
Severity: Medium
CVSS 3.0 •
CVSS 2.0 •
EPSS 0.09%
Vendor Advisory ubuntu.com Vendor Advisory ubuntu.com Vendor Advisory redhat.com Vendor Advisory redhat.com Vendor Advisory redhat.com Vendor Advisory ubuntu.com Vendor Advisory ubuntu.com Vendor Advisory redhat.com Vendor Advisory redhat.com Vendor Advisory kernel.org Vendor Advisory kernel.org
Affected: n/a n/a
Published at:
Updated at:

References

Link Tags
https://usn.ubuntu.com/3903-2/ third party advisory vendor advisory
https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.14.87 patch vendor advisory
https://github.com/torvalds/linux/commit/29ec90660d68bbdd69507c1c8b4e33aa299278b1 third party advisory patch
https://usn.ubuntu.com/3901-2/ third party advisory vendor advisory
https://access.redhat.com/errata/RHSA-2019:0324 third party advisory vendor advisory
https://bugs.chromium.org/p/project-zero/issues/detail?id=1700 issue tracking exploit third party advisory
https://access.redhat.com/errata/RHSA-2019:0202 third party advisory vendor advisory
https://access.redhat.com/errata/RHSA-2019:0163 third party advisory vendor advisory
http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=29ec90660d68bbdd69507c1c8b4e33aa299278b1 third party advisory patch
https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.19.7 patch vendor advisory
https://usn.ubuntu.com/3901-1/ third party advisory vendor advisory
https://usn.ubuntu.com/3903-1/ third party advisory vendor advisory
https://access.redhat.com/errata/RHSA-2019:0831 third party advisory vendor advisory
https://access.redhat.com/errata/RHBA-2019:0327 third party advisory vendor advisory

Frequently Asked Questions

What is the severity of CVE-2018-18397?
CVE-2018-18397 has been scored as a medium severity vulnerability.
How to fix CVE-2018-18397?
To fix CVE-2018-18397, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2018-18397 being actively exploited in the wild?
It is possible that CVE-2018-18397 is being exploited or will be exploited in a near future based on public information. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
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