UDP Port 389 – LDAP (Lightweight Directory Access Protocol)

About UDP Port 389

Port 389 carries the IANA assignment for ldap. The IANA description reads: ‘Lightweight Directory Access Protocol’. This port appears in 1 IDS rule and does not have notable malware activity indicators in our data.

IDS Rule References

1 IDS / security rule reference UDP port 389. Treat that number as context, not a danger score. Many detection rules are written against groups of ports rather than one service, web ports especially, so common web alternate ports inherit large counts while genuinely sensitive services can show few rules or none. Presence in IDS rules does not mean traffic on this port is malicious.

Rule categories (top 1): attempted-dos (1).

Sample rule descriptions for UDP port 389:

• ET EXPLOIT Microsoft LDAP Referral Response Inbound (CVE-2024-49113)

Data Sources

This information is compiled from: IANA Service Name and Transport Protocol Port Number Registry, Emerging Threats Open Ruleset (BSD 2-Clause / GPLv2 per SID range), and Snort Community Rules (GPLv2).