CVE-2018-18386

Severity: low (CVSS 3.3 v3.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2018-10-17 · updated 2026-06-17
Weakness: CWE-704

Description

drivers/tty/n_tty.c in the Linux kernel before 4.14.11 allows local attackers (who are able to access pseudo terminals) to hang/block further usage of any pseudo terminal devices due to an EXTPROC versus ICANON confusion in TIOCINQ.

Affected products

Canonical Ubuntu Linux: 12.04, 14.04
Linux kernel: before 4.14.11 — fixed in 4.14.11

How to fix

Upgrade to a fixed version: Linux kernel 4.14.11. Check the vendor advisory for mitigations.

References

http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=966031f340185eddd05affcf72b740549f056348
https://access.redhat.com/errata/RHSA-2019:0831
https://bugzilla.suse.com/show_bug.cgi?id=1094825
https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.14.11
https://github.com/torvalds/linux/commit/966031f340185eddd05affcf72b740549f056348
https://usn.ubuntu.com/3849-1/
https://usn.ubuntu.com/3849-2/
http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=966031f340185eddd05affcf72b740549f056348
https://access.redhat.com/errata/RHSA-2019:0831
https://bugzilla.suse.com/show_bug.cgi?id=1094825
https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.14.11
https://github.com/torvalds/linux/commit/966031f340185eddd05affcf72b740549f056348

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