CVE-2020-25721 log

Severity Medium
Remote Yes
Type Privilege escalation
A security issue has been found in Samba versions 4.0.0 to 4.15.1. Samba as an AD DC did not provide a way for Linux applications to obtain a reliable SID (and samAccountName) in issued tickets.
Group Package Affected Fixed Severity Status Ticket
AVG-2538 samba 4.15.1-1 4.15.2-1 Medium Fixed

It would be prudent to pre-create disabled users in Active Directory matching on all privileged names not held in Active Directory, eg

 samba-tool user add root -H ldap://$SERVER -U$USERNAME%$PASSWORD --random-password
 samba-tool user add ubuntu -H ldap://$SERVER -U$USERNAME%$PASSWORD --random-password
 (repeat for eg all system users under 1000 in /etc/passwd or special to any other AD-connected services, eg perhaps "admin" for a web-app)

If running a Microsoft Windows Active Directory, setting ms-DS-MachineAccountQuota to 0, in the Active Directory domain would be advised, if possible.