The computing giant didn't fix ProxyNotLogon in October's Patch Tuesday, but it disclosed a rare 10-out-of-10 bug and patched two other zero-days, including one being exploited.
Still no fix for ProxyNotShell Microsoft Exchange bugs theregister.com - get the latest breaking news, showbiz & celebrity photos, sport news & rumours, viral videos and top stories from theregister.com Daily Mail and Mail on Sunday newspapers.
Microsoft has released patches for 84 vulnerabilities in its products on its monthly Patch Tuesday, but failed to deliver fixes for two zero-day flaws.