CVE-2018-25389 affects HaPe PKH 1.1, a PHP-based application with an SQL injection vulnerability. The vulnerability allows unauthenticated attackers to manipulate database queries through the 'nama_kelompok' POST parameter in lap-anggota-kelompok-pdf.php. Attackers can exploit this using time-based blind SQL injection techniques to extract sensitive database information. The vulnerability has been documented with public exploits available, making it a high-risk issue for affected systems.