A slab-out-of-bounds read in fbcon in the Linux kernel before 5.9.7 could be used by local attackers to read privileged information or potentially crash the kernel, aka CID-3c4e0dff2095. This occurs because KD_FONT_OP_COPY in drivers/tty/vt/vt.c can be used for manipulations such as font height.
http://www.openwall.com/lists/oss-security/2020/11/25/1
https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.9.7
https://lists.debian.org/debian-lts-announce/2020/12/msg00015.html
https://lists.debian.org/debian-lts-announce/2020/12/msg00027.html
Source: MITRE
Published: 2020-11-20
Updated: 2021-01-27
Type: CWE-125
Base Score: 6.1
Vector: AV:L/AC:L/Au:N/C:P/I:P/A:C
Impact Score: 8.5
Exploitability Score: 3.9
Severity: MEDIUM
Base Score: 5
Vector: CVSS:3.1/AV:P/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:H
Impact Score: 4.7
Exploitability Score: 0.3
Severity: MEDIUM