LDAP server must sign all traffic sent to the client.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-4407	AD.3106_2008	SV-41837r1_rule	ECSC-1	Medium

Description
By default, LDAP traffic is unsigned, which makes this traffic vulnerable to man . in . the . middle attacks. In this type of attack, an intruder captures packets between the server and the client and modifies them before forwarding them to the client. In the case of an LDAP server, this means that an attacker could cause a client to make decisions based on false records from the LDAP directory. This setting requires that the domain controller signs data sent to the client, which allows the client to verify that the data was not modified in transit. This is important because the client makes security decisions based on LDAP query results. For instance, member servers rely on LDAP queries to find out group membership or to determine which group policy objects should apply. If this policy is configured as 'none', the server will not require data signatures but will provide them if requested by the client. The 'Require signature' term means the domain contfoller will only bind with clients that negotiate LDAP data.

Description

By default, LDAP traffic is unsigned, which makes this traffic vulnerable to man . in . the . middle attacks. In this type of attack, an intruder captures packets between the server and the client and modifies them before forwarding them to the client. In the case of an LDAP server, this means that an attacker could cause a client to make decisions based on false records from the LDAP directory. This setting requires that the domain controller signs data sent to the client, which allows the client to verify that the data was not modified in transit. This is important because the client makes security decisions based on LDAP query results. For instance, member servers rely on LDAP queries to find out group membership or to determine which group policy objects should apply. If this policy is configured as 'none', the server will not require data signatures but will provide them if requested by the client. The 'Require signature' term means the domain contfoller will only bind with clients that negotiate LDAP data.

STIG	Date
Windows 2008 Domain Controller Security Technical Implementation Guide	2013-07-03

Details

Check Text ( C-345r1_chk )
Further policy details: Configure the policy value for Computer Configuration -> Windows Settings -> Security Settings -> Local Policies -> Security Options -> “Domain Controller: LDAP Server signing requirements” to “Require signing”. The policy referenced configures the following registry value: Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \System\CurrentControlSet\Services\NTDS\Parameters\ Value Name: LDAPServerIntegrity Value Type: REG_DWORD Value: 2 Documentable Explanation: If LDAP Signing is not supported by a client, service or application then this must be documented with the IAO with supporting vendor information. Check procedure: 1. Analyze the system using the Security Configuration and Analysis snap-in. Expand the Security Configuration and Analysis tree view. 2. Navigate to Local Policies -> Security Options. 3. If the value for “Domain Controller: LDAP Server signing requirements” is not set to “Require signing”, then this is a finding.

Check Text ( C-345r1_chk )

Further policy details:
Configure the policy value for Computer Configuration -> Windows Settings -> Security Settings -> Local Policies -> Security Options -> “Domain Controller: LDAP Server signing requirements” to “Require signing”.

The policy referenced configures the following registry value:

Registry Hive: HKEY_LOCAL_MACHINE
Registry Path: \System\CurrentControlSet\Services\NTDS\Parameters\

Value Name: LDAPServerIntegrity

Value Type: REG_DWORD
Value: 2

Documentable Explanation: If LDAP Signing is not supported by a client, service or application then this must be documented with the IAO with supporting vendor information.

Check procedure:
1. Analyze the system using the Security Configuration and Analysis snap-in. Expand the Security Configuration and Analysis tree view.

2. Navigate to Local Policies -> Security Options.

3. If the value for “Domain Controller: LDAP Server signing requirements” is not set to “Require signing”, then this is a finding.

Fix Text (F-5737r1_fix)
Configure Domain Controller to require LDAP access signing.