The LDAP protocol can deal in quite a bit of sensitive data: Active Directory usernames, login attempts, failed-login notifications, and more. If attackers get ahold of that data in flight, they might be able to compromise data like legitimate AD credentials and use it to poke around your network in search of valuable assets.
Encrypting LDAP traffic in flight across the network can help prevent credential theft and other malicious activity, but it's not a failsafe—and if traffic is encrypted, your own team might miss the signs of an attempted attack in progress.
For example, if an attacker is using brute force to try and gain access to a restricted database or storage area, that attack will leave network artifacts such as "failed login" messages which are also transmitted across the network using the LDAP protocol. If you've encrypted LDAP traffic as a protective measure, you'll need decryption capabilities to detect those failed login messages associated with sensitive assets.
Advanced LDAP encryption is key to good cybersecurity, but so are smart implementations and the ability to decrypt traffic without compromising your other security controls. Scroll down for more answers to your LDAP questions, or learn how to safely implement TLS 1.3 with passive decryption here.
Frequently Asked Questions About LDAP:
1.) Is LDAP encrypted?
Short answer: no. Longer answer: While LDAP encryption isn't standard, there is a nonstandard version of LDAP called Secure LDAP, also known as "LDAPS" or "LDAP over SSL" (SSL, or Secure Socket Layer, being the now-deprecated ancestor of Transport Layer Security).
LDAPS uses its own distinct network port to connect clients and servers. The default port for LDAP is port 389, but LDAPS uses port 636 and establishes TLS/SSL upon connecting with a client.
2.) Is LDAP authentication secure?
LDAP authentication is not secure on its own. A passive eavesdropper could learn your LDAP password by listening in on traffic in flight, so using SSL/TLS encryption is highly recommended.
3.) Is LDAP port 389 secure?
Not exactly. The port itself is no more secure than unencrypted LDAP traffic, but you do have some alternatives to LDAPS for increasing your security: you could use the LDAPv3 TLS extension to secure your connection, utilize the StartTLS mode to transition to a TLS connection after connecting on port 389, or set up an authentication mechanism to establish signing and encryption.
4.) What is the difference between LDAP and Active Directory?
Both LDAP and Active Directory are directory services, but although the Active Directory protocol builds on the LDAP protocol, AD is proprietary to Microsoft and requires a Microsoft Domain Controller to function.