Finding and Fixing Vulnerabilities in LDAP Null Directory Bases, a Medium Risk Vulnerability

With Notes on Remediation, Penetration Testing, Disclosures, Patching and Exploits

Vulnerabilities in LDAP Null Directory Bases is a Medium risk vulnerability that is one of the most frequently found on networks around the world. This issue has been around since at least 1990 but has proven either difficult to detect, difficult to resolve or prone to being overlooked entirely.

Vulnerability Name:LDAP Null Directory Bases
Test ID:1467
Risk:Medium
Category:Simple Network services
Type:Attack
Summary:Your LDAP server will allow the directory BASE to be set to NULL. This allows information to be collected without any prior knowledge of the directory structure.Coupled with a NULL BIND, an anonymous user can query your LDAP server using a tool such as 'LdapMiner'
Impact:Attackers can gain critical information about the host.
Solution:Disable NULL BASE queries on your LDAP server
More Information:http://www.openldap.org/lists/openldap-software/200402/msg00139.html
http://seclists.org/basics/2008/Aug/212
http://securitysynapse.blogspot.com/2013/09/dangers-of-ldap-null-base-and-bind.html

Scanning For and Finding Vulnerabilities in LDAP Null Directory Bases

Use of Vulnerability Management tools are standard practice for the discovery of this vulnerability. The primary failure of VA in finding this vulnerability is related to setting the proper scope and frequency of network scans. It is vital that the broadest range of hosts (active IPs) possible are scanned and that scanning is done frequently. We recommend weekly. Your existing scanning solution or set of test tools should make this not just possible, but easy and affordable. 

Penetration Testing (pentest) for this Vulnerability

The Vulnerabilities in LDAP Null Directory Bases is prone to false positive reports by most vulnerability assessment solutions. Fortra VM uses behavior based testing that eliminates this issue. For all other VA tools security consultants will recommend confirmation by direct observation. In any case Penetration testing procedures for discovery of Vulnerabilities in LDAP Null Directory Bases produces the highest discovery accuracy rate, but the infrequency of this expensive form of testing degrades its value. The ideal would be to have pentesting accuracy and the frequency and scope possibilities of VA solutions.

Security Updates on Vulnerabilities in LDAP Null Directory Bases

Given that this is one of the most frequently found vulnerabilities, there is ample information regarding mitigation online and very good reason to get it fixed. Hackers are also aware that this is a frequently found vulnerability and so its discovery and repair is that much more important. It is so well known and common that any network that has it present and unmitigated indicates "low hanging fruit" to attackers.

Disclosures related to this vulnerability

http://seclists.org/basics/2008/Aug/212

Patching/Repairing this Vulnerability

Vulnerabilities in LDAP Null Directory Bases is a Medium risk vulnerability that is also high frequency and high visibility. This is the most severe combination of security factors that exists and it is extremely important to find it on your network and fix it as soon as possible.

See how vulnerability scanning can help your online security.