Open CIFS
Determine if UDP port 445 for CIFS is open to the public
While some ports such as HTTP and HTTPS are required to be open to the public to function properly, more sensitive services such as CIFS should be restricted to known IP addresses.
Recommended Actions
Follow the appropriate remediation steps below to resolve the issue.
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Log into the Microsoft Azure Management Console.
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Select the serach bar at the top and search for Network security groups.
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Select the “Network security group” that needs to be verified.
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Click on the “Name” of the selected “Network security group” to access the port configurations.
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In the “Overview” tab scroll down the page and check the “Inbound security rules” under the Settings .
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If the “CIFS” for port 445 with protocol “UDP” is showing as “Allow” for all “Source” and “Destination” then the selected “Network security group” has UDP port 445 for CIFS open to the public.
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Repeat steps number 2 - 6 to verify other “Network security groups”.
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Navigate to the “Network security group” and select the security group that needs to modify for restricting the CIFS protocol on port 445 to specific IP Address.
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Scroll down the left navigation panel and choose “Inbound security rules” under “Settings”.
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Click on the “Name” column of the “CIFS” protocol that needs to be modified. Under “Source” select the “IP Addresses” from the dropdown menu and enter the “Source IP addresses/CIDR ranges” as per the requirement, select the required Protocol and Action and click on the “Save” option at the top of the pane.
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Repeat step number 8 - 10 to restrict UDP port 445 to known IP addresses.