[Samba] Due to CVE in windows, disable SMB3 compression.

[L.P.H. van Belle]

https://portal.msrc.micro...idance/advisory/adv200005
Published: 03/10/2020
 
Workarounds

The following workaround may be helpful in your situation. In all cases, Microsoft strongly recommends that you install the updates for this vulnerability as soon as they become available even if you plan to leave this workaround in place:

Disable SMBv3 compression

You can disable compression to block unauthenticated attackers from exploiting the vulnerability against an SMBv3 Server with the PowerShell command below.

Set-ItemProperty -Path "HKLM:\SYSTEM\CurrentControlSet\Services\LanmanServer\Parameters" DisableCompression -Type DWORD -Value 1 -Force

Notes:

No reboot is needed after making the change.
This workaround does not prevent exploitation of SMB clients.

You can disable the workaround with the PowerShell command below.

Set-ItemProperty -Path "HKLM:\SYSTEM\CurrentControlSet\Services\LanmanServer\Parameters" DisableCompression -Type DWORD -Value 0 -Force