When the DHS says “all civilian federal agencies” must take some action relative to security, it usually means something interesting is going on. Zerologon: instantly become domain admin by subverting Netlogon cryptography (CVE-2020-1472)
To be vulnerable to this issue, you must NOT have applied the patch that was issued by Microsoft in August. That is from more than 6 weeks ago.
Last month, Microsoft patched a very interesting vulnerability that would allow an attacker with a foothold on your internal network to essentially become Domain Admin with one click. All that is required is for a connection to the Domain Controller to be possible from the attacker’s viewpoint.
I assume that folks currently employed in the security arena know about this already, but whenever DHS says do something “Now!” my curiosity is heightened.
Here are the directives from DHS Cybersecurity. Under the law, civilian federal agencies have to do this.
1. Update all Windows Servers with the domain controller role by 11:59 PM EDT, Monday, September 21, 2020,
- Apply the August 2020 Security Update to all Windows Servers with the domain controller role. If affected domain controllers cannot be updated, ensure they are removed from the network.
- By 11:59 PM EDT, Monday, September 21, 2020, ensure technical and/or management controls are in place to ensure newly provisioned or previously disconnected domain controller servers are updated before connecting to agency networks.
Now I know that patches on Patch Tuesday can cause problems. But if you have this vulnerability un-patched, you are going to have many more problems than a few disgruntled users.


