PCI scan - CIFS NULL Session Permitted

Hello - I am currently going through a PCI audit and they found the below vulnerability.

3.1.5. CIFS NULL Session Permitted

The policy "Network access: Named pipes that can be accessed anonymously" has netlogon,samr,lsarpc in the list. I believe this is where the vulnerability came from. I understand they are ldap services but do I need to allow them via anonymous access? is there a more secure method for these services to use?
agcsupportAsked:
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btanConnect With a Mentor Exec ConsultantCommented:
Suggest you go to the server and take steps for disabling SMB/NETBIOS NULL Session on domain controllers using group policy.

Enable:
Network access: Restrict Anonymous access to Named Pipes and Shares
Network access: Do not allow anonymous enumeration of SAM accounts
Network access: Do not allow anonymous enumeration of SAM accounts and shares
Network access: Shares that can be accessed anonymously

Disable:
Network access: Let Everyone permissions apply to anonymous users
Network access: Allow anonymous SID/Name translation

Also update the registry key values to restrict null session as below:

HKEY\SYSTEM\CurrentControlSet\Control\Lsa:
RestrictAnonymous = 1
Restrict AnonymousSAM = 1
EveryoneIncludesAnonymous = 0
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agcsupportAuthor Commented:
@lvl60 - I previously found that article and applied the settings. The below setting allows you to add named pipes basically as an exception. This is where I have the netlogon,samr,lsarpc listed. I did not manually input them so I would have to say they are there by default. These are the services I am wanting to disable if possible. If they are required ldap pipes then I will report them as needed pipes to auditors.

"Network access: Restrict Anonymous access to Named Pipes and Shares"
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btanExec ConsultantCommented:
Those are default named pipes e.g. default list on Windows Server 2003, R2: COMNAP, COMNODE, SQL\QUERY, SPOOLSS, netlogon, lsarpc, samr, browser. There is really no need for these to have anonymous login. User account should authenticated for accountability and audit trail..
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The Lifecycle Approach to Managing Security Policy

Managing application connectivity and security policies can be achieved more effectively when following a framework that automates repeatable processes and ensures that the right activities are performed in the right order.

 
agcsupportAuthor Commented:
So is it your opinion I can remove these entries without issue?

Netlogon - Net Logon service
 Lsarpc - LSA access
 Samr - SAM access
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btanExec ConsultantCommented:
Yes. As MS stated
In operating systems earlier than Windows Server 2003 with Service Pack 1 (SP1), these named pipes were allowed anonymous access by default. In later operating systems, these pipes must be explicitly added if needed.
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agcsupportAuthor Commented:
I looked at both of my server 2012 DC's and they have the three named pipes enabled. I also looked on another 2012 server where the policy was set to restrict and there were no services listed. Seems that the domain controllers have them enabled by default which leads me to think they are needed. I suppose I can remove them and see what breaks but not a fan of doing that.
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sAMAccountNameSr. Systems EngineerCommented:
So is it your opinion I can remove these entries without issue?

Id suggest caution here...

Given you understand what dependencies exist in your network which may rely on  this functionality, you are best suited to answer this.  I dont think anyone here, with zero knowledge of what is going on at your company can say you can do this without issue.

That said, the spirit of btan's reply rings true
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agcsupportAuthor Commented:
Completely understand nobody here knows my environment and its dependencies. Lets say I set up a 2012 domain test environment. Two DCs and one Win10 workstation with all default settings including the named pipes exceptions. Do I need these services for this environment to work correctly.
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sAMAccountNameSr. Systems EngineerCommented:
You shouldnt with modern versions of the operating system and server roles.  As btan pointed out, this is legacy stuff
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agcsupportAuthor Commented:
Thank you everyone for your help - much appreciated.
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