The ext4_xattr_check_entries function in fs/ext4/xattr.c in the Linux kernel through 4.15.15 does not properly validate xattr sizes, which causes misinterpretation of a size as an error code, and consequently allows attackers to cause a denial of service (get_acl NULL pointer dereference and system crash) via a crafted ext4 image.
http://openwall.com/lists/oss-security/2018/03/29/1
https://access.redhat.com/errata/RHSA-2018:2948
https://bugzilla.kernel.org/show_bug.cgi?id=199185
https://bugzilla.redhat.com/show_bug.cgi?id=1560793
Source: MITRE
Published: 2018-04-02
Updated: 2018-10-31
Type: CWE-476
Base Score: 7.1
Vector: AV:N/AC:M/Au:N/C:N/I:N/A:C
Impact Score: 6.9
Exploitability Score: 8.6
Severity: HIGH
Base Score: 5.5
Vector: CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
Impact Score: 3.6
Exploitability Score: 1.8
Severity: MEDIUM