ICMP Timestamp Request Remote Date Disclosure

Question

How to fix ("ICMP Timestamp Request Remote Date Disclosure") for Windows servers

Answer 1

Hello Jay Tee,

Thank you for posting in Q&A forum.

To address the "ICMP Timestamp Request Remote Date Disclosure" issue on Windows Server 2019, you can follow these steps:

1. You can disable ICMP Timestamp Reply by modifying the registry. Please back up the registry before making any changes. Here are the steps:

• Open the Registry Editor (regedit).

• Navigate to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters.

• Create a new DWORD value named DisableICMPRedirect and set its value to 1.

• Restart the server for the changes to take effect.

2. You can also use Windows Firewall to block ICMP Timestamp requests and replies:

• Open the Windows Firewall with Advanced Security.

• Create a new inbound rule to block ICMPv4 and ICMPv6 Echo Request messages.

• Create a new outbound rule to block ICMPv4 and ICMPv6 Echo Reply messages.

I hope the information above is helpful.

If you have any questions or concerns, please feel free to let us know.

Best Regards,

Daisy Zhou

============================================

If the Answer is helpful, please click "Accept Answer" and upvote it.

Answer 2

Hi Jay Tee,

Firewall rules take effect immediately after creation/modification.

No system restart is required for Windows Firewall changes to apply.

I would like to add option 3

# Create firewall rule to block ICMP Timestamp requests
New-NetFirewallRule -DisplayName "Block ICMP Timestamp" -Direction Inbound -Protocol ICMPv4 -IcmpType 13 -Action Block -Enabled True

Best regards,

Alex

P.S. If my answer help to you, please Accept my answer