A Boolean-based blind SQL injection vulnerability exists in the `/api/v1/contenttype` endpoint. The endpoint utilizes the `sites` query parameter, which accepts a comma-separated list of site identifiers or keys. The `sites` parameter is directly concatenated into a SQL query without proper sanitization, allowing an authenticated attacker with low privileges to extract data from the database, perform privilege escalation, or trigger denial-of-service conditions. Exploitation was verified using tools such as SQLMap, enabling full database exfiltration and potential denial-of-service conditions via crafted payloads.