While the days of bank heists on horseback are history, the allure of fast and easy cash still fascinates modern-day outlaws.
Today, there’s easy money to be had from data. Stolen data can be sold on the Dark Web or used to commit illegal acts that result in lucrative paydays.
Ransomware is now one of the most popular avenues for attackers to gain both data AND cash. Another avenue that’s less well-known is code injection attacks like LDAP injection.
These attacks are particularly insidious – because of the large amount of data attackers can steal. But how is this done?
Below, we explain the role LDAP plays in securing data, and we reveal our top strategies for protecting your business from exploits targeting it.
What Is LDAP and Why Is It important?
Definition and explanation
Lightweight Directory Access Protocol (LDAP) is used to access and manage directory services over a TCP/IP network. Originally defined in RFC 1777 in 1995, it’s a lightweight protocol that needs far less computing power and network resources to operate than its predecessor X.500
This directory access or data query protocol acts like a phone book for your network system It organizes staff information like phone numbers, locations, email addresses, roles, onboarding dates, and user permissions.
When you or an employee needs to find information, you make queries in Active Directory, and the requested information is retrieved.
Now, we’re often asked, “Is LDAP still used?”
The answer is yes.
Today, it integrates with protocols like SAML, OAuth 2.0, and OpenID Connect to enable Single Sign-On (SSO) and federated identity management (FIM). This streamlines user authentication and authorization across diverse platforms.
More importantly, LDAPS has emerged as a secure alternative. Unlike LDAP (which transmits data in plain text), LDAPS uses the SSL/TLS cryptographic protocols to encrypt traffic.
We’ll talk more about LDAPS as we explore use cases below.
Benefits and advantages of LDAP
Today, LDAP is used in Microsoft’s Active Directory.
Other directories that use it include Red Hat Directory Server, Oracle Internet Directory, Apache Directory Server, and IBM Security Directory Server.
This directory access protocol has several benefits and advantages:
- Centralized authentication: LDAP provides a centralized repository for authentication and authorization. For example, Rutgers University uses an LDAP-based Active Directory to manage student, staff, and faculty credentials in one place, enabling SSO for accessing emails, student resources, enterprise file storage, secure print release, and collaboration tools.
- Scalability: This protocol can handle large volumes of entries efficiently, making it suitable for businesses with extensive user databases and resource directories. For example, large corporations like Google and Amazon use LDAP to authenticate users and customers across their wide array of services and applications.
- Interoperability: LDAP ensures compatibility with diverse systems. This interoperability is critical for businesses like Amazon.
For example, directories use the protocol to access and manage user attributes and interactions, such as past orders, returns, and browsing history. Because of this, Amazon can offer personalized product recommendations to users. So, if someone frequently buys cat food, they might receive tailored suggestions for cat treats, vitamins, or water fountains.
This type of directory also integrates with Amazon’s CRM systems, so customer service reps have access to user profiles and order history. If a customer contacts Amazon with an issue about a recent order, the rep can immediately access the details without requesting further information. Not having to repeat previously shared details reduces frustration and stress. This increases consumer trust and goodwill towards Amazon.
- Flexibility: LDAP supports a wide range of attributes and object classes, allowing organizations to tailor the directory to their business needs. For example, a hospital can use this directory access protocol to manage patient history, medication records, staff schedules, patient flow, and billing records.
More common use cases
Besides the above use cases, the more secure alternative LDAPS has been increasingly adopted as the standard for directory services.
Because LDAPS uses SSL/TLS to encrypt traffic, it’s less vulnerable against threats like packet sniffing and Adversary-in-the-Middle (AiTM) attacks.
Starting with Windows Server 2022, Microsoft has enforced channel binding and signing to enable secure communications between LDAP clients and Active Directory domain controllers, significantly reducing the prevalence of these attacks.
Since all data in transit is encrypted, attackers can’t read or modify the data, even if they manage to intercept it. They also can’t decipher the content of network packets, even if they manage to capture them.
Before we discuss how this data query protocol works, here’s a quick quiz:
Which of the following are examples of lightweight directory access protocols?
- OpenLDAP
- LDAPv3
- X.500
- LDAPS
If you answered, “all of them,” pat yourself on the back. OpenLDAP is an open-source implementation of LDAP. It’s platform agnostic and highly customizable. However, it takes high-level skills to configure successfully.
If, however, you’re an SMB or larger business that uses cloud computing platforms like Azure, Google Cloud, or AWS, OpenLDAP better integrates with various cloud-based services and applications.
Next, LDAPv3 (published in 1997) is the current version of LDAP.
Meanwhile, LDAPS is the most secure version, where data is encrypted in transit. And finally, LDAP is a “lightweight” version of the X.500 directory service framework.
How Does LDAP work?
Architecture and components
This directory access protocol follows a client-server architecture:
Clients: These are applications that request information from Active Directory
Servers or Directory System Agents: These are systems that store and manage Active Directory data. In Active Directory, data is organized in a hierarchical structure, and each entry has a unique identifier called a Distinguished Name (DN). A Distinguished Name is made up of a set of identifiers called Relative Distinguished Names (RDN).
The Root DSE (Directory Service Entry) is the starting point of this hierarchy. It sits at the top of what is called the Directory Information Tree (DIT).
Distributed Directories: Multiple servers serve to provide a unified view of the directory.
Protocol operations
users can make queries that result in the server performing several operations.
These operations include:
- Search: allows clients to retrieve entries from the directory that match search criteria
- Add: used to add new entries to the directory
- Delete: removes entries from the directory
- Modify: updates the attributes of existing entries in the directory
- Bind: authenticates clients to the server
- Unbind: closes the connection to the server
- Compare: checks if an entry contains a specific attribute value
Data models and schemas
Four models describe the various aspects of an LDAP directory. They are the:
- Security model: this provides an authentication mechanism for clients and protects the directory from unauthorized access.
- Information model: this provides the structures necessary for building the directory tree. An entry is a basic unit and is represented as a node in the Directory Information Tree (DIT).
- Naming model: this defines how entries in the DIT are identified. Each entry has an attribute called the Relative Distinguished Name (RDN).
- Functional model: this defines what operations can be performed to access or modify server entries. Access is facilitated by bindings, searches, reads, and writes.
Meanwhile, schemas define the structure and rules for directory data. It tells us what object classes can be stored, what they can be named, and what attributes they must contain.
- Attribute types: this specifies the characteristics of attributes, including syntax and matching rules
- Object classes: this defines the collections of attribute types that can be used in entries containing that class
- Syntaxes: this determines the structure and content of entries in the directory
- Matching rules: this specifies how comparisons should be performed on attribute values during searches
- Name forms: These specify how entries can be named.
Examples of Lightweight Directory Access Protocol
User validation and authentication
When a user attempts to access an application, the application can use LDAP to validate the user’s credentials:
- User enters credentials such as username and password
- The application sends a “bind” request to the LDAP server.
- The server validates the credentials against its directory.
- If the credentials match, the server returns a “success” response. Otherwise, it returns a failure response.
There are two ways to authenticate in an LDAP-based directory:
- Simple authentication with traditional username and password
- SASL (Simple Authentication and Security Layer) authentication. This adds another layer of security by binding the server to Kerberos, another authentication protocol.
Single sign on
LDAP can be used to facilitate SSO, where users can gain access to resources with just a one-time authentication.
As mentioned, this data query protocol can integrate with protocols like SAML, OAuth 2.0, and OpenID Connect to enable SSO. Here’s how it works:
Integration with SAML
- Authentication: When the user logs in to the Service Provider (SP), they are redirected to the Identity Provider (IdP)
- Verification: The IdP queries the directory to verify the user’s credentials.
- Assertion: Upon successful verification, the IdP generates a SAML assertion that contains user attribute info.
- Authorization: The SAML assertion is sent back to the SP, which grants access based on the information in the assertion.
Integration with OAuth 2.0
- Authentication: When a user attempts to access an application, the application redirects to the OAuth Authorization Server’s login page. The server then uses the directory to verify credentials.
- Token Issuance: Once verified, the OAuth Authorization Server provides an authorization code, which the application exchanges for an access token.
- Authorization: The application then presents the token to the Resource Server (API) to gain access to the requested resource for the user.
Integration with OpenID Connect
- Authentication: Like OAuth, the OpenID Provider (OP) queries the directory to verify the user’s credentials.
- ID Token Issuance: If credentials check out, the OpenID Provider issues an OpenID Connect token to the application.
- Authorization: The application uses the token to grant access to the user.
Authorization
As mentioned, a domain controller manages the authentication and authorization process in Active Directory.
Let’s talk about what LDAP authorization would look like for Electra Cruise, a fictional car manufacturer that uses Active Directory.
The manufacturer’s directory might include information like user credentials, roles, access rights, and data pertaining to departments like:
- Engineering & Design
- Sales & Marketing
- Research & Development (R&D)
- Finance & Accounting
- Supply Chain & Logistics
Our car manufacturer would also need strict access control policies to protect proprietary technologies and intellectual property.
So, we would use our directory access protocol to retrieve user authorization info and determine access to development tools, CAD systems, and testing environments. This ensures only authorized employees can view and make changes to sensitive data.
To that end, we would integrate with protocols like SAML, OAuth 2.0, and OpenID Connect to implement role-based access control (RBAC), JIT (just-in-time) access, and least privilege access.
So, engineers would be authorized to access testing data and design schematics, while sales personnel would only see customer data, inventory levels, lead tracking, customer feedback, and sales reports.
Limiting access would reduce the exposure of trade secrets and minimize the risk of insider threats.
Hierarchy of LDAP Directory
LDAP uses an hierarchical data model organized in a tree-like structure:
- Entries: these are basic units of information, representing objects
- Distinguished Names (DN): these are unique identifiers for entries, specifying their location in the directory tree
- Attributes: key value pairs that store information about an entry
- Object classes: this defines the types of attributes an entry must have
Root directory
LDAP directories are structured like trees, with roots and branches representing various levels of the hierarchy. The root directory is the top-most entry in the directory tree or Directory Information Tree (DIT). It’s identified with DC (domain component) or dc=com.
Countries
Below the root, the directory can be sub-divided into country-specific entries.
Each country is represented by two letters, so the United Kingdom is c=UK and the United States would be c=US
Organizations
Within each country, there can be multiple organizations.
Each organization is represented by its name, such as o=GoogleOrg or o=Meta
Organizational Units (OUs)
Within each organization, there can be multiple organizational units, such as the marketing, HR, compliance, IT support, and sales departments.
Each organizational unit is represented by its name, such as ou=Marketing or ou=HR.
Individuals
Within each organizational unit, there are individual entries representing users.
Users are often represented by their User ID, such as uid=mjenkins
The complete path from the individual entry up to the root forms the Distinguished Name (DN) of that entry. For example, a DN might look like this:
Uid=mjenkins, ou=Marketing, o=Meta, c=UK
LDAP vs. Active Directory: Understanding the Differences
Comparing LDAP and Active Directory
First, LDAP is a directory access or data query protocol that sets the rules of communication between users and a directory. Meanwhile, Active Directory AD) is a database that stores user information and resources. AD uses LDAP as the standard for how users communicate with its domain controller.
In Active Directory, a domain controller is a server that accepts user queries, implements user authentication & authorization, and allows access to resources.
Ultimately, LDAP uses schemas to organize information in the Directory Information Tree and in turn, secure LDAP (LDAPS) is used to facilitate secure communications between the user and Active Directory.
Pros and cons of LDAP and Active Directory
Although we can’t directly compare both, we can discuss their pros and cons in terms of how they work together to facilitate secure communications.
|
|
LDAP |
AD |
|
Name |
Lightweight Directory Access Protocol |
Active Directory |
|
Description |
An authentication and authorization protocol |
A Microsoft directory service. |
|
Architecture |
Based on a client-server model, with a Directory Information Tree (DIT) and unique Distinguished Names (DN) for each entry. |
Considerably more complex and includes domain controllers, forests, domains, organizational units (OU), group policy objects (GPO), and a global catalog |
|
Security |
Provides secure communications through LDAPS and SASL. SASL binds the server to another authentication mechanism like Kerberos to authenticate users securely. |
LDAP enables queries in Active Directory. The server in Active Directory supports LDAPS and SASL/Kerberos authentication. |
Choosing the right solution for your organization
Because LDAP is a protocol and Active Directory is a database, another comparison may better serve your business needs.
You might decide whether you’d prefer an LDAP or OpenLDAP directory.
Choosing the right solution would depend upon these four (4) factors:
- Do you have a non-Windows environment? If so, OpenLDAP might be more suitable. It offers better support for Linux environments.
- If you have a Windows environment, LDAP integrates seamlessly with products within the Microsoft infrastructure.
- Do you have a complex database of business resources? For a large hospital with complex transactions (patient records linked to multiple doctors, treatments, and appointments), you might combine OpenLDAP and a RDBMS database to manage those complex transactions and protect data integrity. However, be aware that you’ll need a robust team of engineers for support.
- Is cost a factor? If so, OpenLDAP would be your best bet -- if you don’t require professional help for custom development.
Implementing LDAP in Your Organization
Steps to set it up
If you’re ready to leverage this powerful protocol to protect your business from LDAP injection attacks, here are the steps you should take:
- Choose and install a directory that meets your business needs, such as Microsoft Active Directory.
- Install Active Directory Domain Services (AD DS) and Active Directory Certificate Services (AD CS).
- Configure LDAPS over port 636 and configure the Domain controller: LDAP server signing requirements policy to require signing.
- Use ldp.exe to perform tests to verify the LDAPS connection.
- Be sure to populate the directory with the necessary entries such as user data, security groups, and department resources.
- Configure applications to integrate with Active Directory.
- Regularly review logs to track the server’s performance and identify query manipulations.
Best practices for implementation
Implementing LDAP properly is critical to the security of your business. Follow these best practices for optimum results:
- Carefully plan your schema definitions, OUs, and access control policies.
- Use a hierarchical structure that closely mirrors your organization’s hierarchy for easier management and scalability.
- Implement secure LDAPS to encrypt data in transit and consider integrating Active Directory with Entra ID and a password manager like LastPass to enable federated SSO. Sign up for a free LastPass trial here.
- Implement security monitoring and alerting to track unauthorized access attempts.
- Consider indexing frequently queried attributes to improve search efficiency.
- Keep your server software regularly patched to prevent exploits against known vulnerabilities.
- Finally, implement least privilege and rigorously sanitize user inputs to prevent LDAP injection attacks.
Common challenges and how to overcome them
As in all things cybersecurity, implementation is only half the battle.
The other half is solving challenges, so they don’t hamper productivity and business continuity.
Below, we discuss two of the biggest challenges in leveraging this data query protocol and how to overcome them:
- Complex Configuration: Depending on your business needs, configuring this protocol and integrating it with the necessary tools may be prohibitively challenging.
Solution: Use industry configuration tools to simplify the process.
- Security Risks: LDAP can be vulnerable to attacks.
Solution: Use LDAPS and Kerberos to enforce robust authentication and authorization mechanisms.
To take an important step in securing your business, Start your LastPass trial today.
