CVE-2018-18690

Severity: medium (CVSS 5.5 v3.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.7% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2018-10-26 · updated 2026-06-17
Weakness: CWE-754

Description

In the Linux kernel before 4.17, a local attacker able to set attributes on an xfs filesystem could make this filesystem non-operational until the next mount by triggering an unchecked error condition during an xfs attribute change, because xfs_attr_shortform_addname in fs/xfs/libxfs/xfs_attr.c mishandles ATTR_REPLACE operations with conversion of an attr from short to long form.

Affected products

Canonical Ubuntu Linux: 12.04, 14.04, 16.04, 18.04
Debian Linux: 8.0
Linux kernel: before 4.17 — fixed in 4.17

How to fix

Upgrade to a fixed version: Linux kernel 4.17. Check the vendor advisory for mitigations.

References

http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=7b38460dc8e4eafba06c78f8e37099d3b34d473c
http://www.securityfocus.com/bid/105753
https://bugzilla.kernel.org/show_bug.cgi?id=199119
https://bugzilla.suse.com/show_bug.cgi?id=1105025
https://github.com/torvalds/linux/commit/7b38460dc8e4eafba06c78f8e37099d3b34d473c
https://lists.debian.org/debian-lts-announce/2019/03/msg00017.html
https://lists.debian.org/debian-lts-announce/2019/03/msg00034.html
https://lists.debian.org/debian-lts-announce/2019/04/msg00004.html
https://usn.ubuntu.com/3847-1/
https://usn.ubuntu.com/3847-2/
https://usn.ubuntu.com/3847-3/
https://usn.ubuntu.com/3848-1/

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