vcs_write in drivers/tty/vt/vc_screen.c in the Linux kernel through 5.3.13 does not prevent write access to vcsu devices, aka CID-0c9acb1af77a.
5.3.0-18.195.3.0-24.265.4.0-9.126.8.0-31.316.5.0-9.93.11.0-12.194.2.0-16.194.2.0-17.214.2.0-19.234.3.0-1.104.3.0-2.114.3.0-5.164.3.0-6.174.3.0-7.184.4.0-2.164.13.0-16.195.13.0-19.195.3.0-1003.35.3.0-1008.95.3.0-1009.105.3.0-1010.115.4.0-1005.54.4.0-1002.25.13.0-1005.6Exploitability
AV:LAC:LPR:LUI:NScope
S:UImpact
C:HI:HA:HCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H