In UNIX Fourth Research Edition (v4), the su command is vulnerable to a buffer overflow due to the 'password' variable having a fixed size of 100 bytes. A local user can exploit this to gain root privileges. It is unlikely that UNIX v4 is running anywhere outside of a very small number of lab environments.
Exploitability
AV:LAC:HPR:NUI:NScope
S:UImpact
C:HI:HA:H7.4/CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:HMemory Safety